PAYLOAD ransomware attacks through Active Directory GPO通过 Active Directory GPO 进行 PAYLOAD 勒索软件攻击
Kaspersky GERT experts dive into the technical incident analysis of PAYLOAD ransomware: an encryptionless, binary-less operation that abused Active Directory mechanisms for managing Group Policy Objects.

Group Policy as an attack surface
The win Firewall Off GPO
The one-day delay detonation
Detection engineering
Anti-forensics and recovery-inhibition capabilities
Confirmed PAYLOAD family capabilities
Windows Event Log clearing
Security process and service termination
VSS deletion, backup and recovery suppression
Ecosystem-relevant ransomware techniques
ETW suppression and in-memory patching
Vulnerable signed driver abuse, BYOVD
ESXi security policy weakening
Phase 1 — domain controller actions (to be performed first)
Phase 2 — Active Directory and GPO hardening
Phase 3 — credential and access hardening
Phase 4 — detection and monitoring
Detection by Kaspersky solutions
MITRE ATT&CK mapping
Indicators of compromise
In April 2026, we at Kaspersky’s Global Emergency Response Team (GERT) responded to a security incident at a manufacturing organization in the Middle East. The threat actor obtained domain admin-equivalent control of the organization’s Active Directory environment and authored a malicious Group Policy Object (GPO) named PAYLOAD, linking it at the domain root. Through that single object, the actor delivered ransom notes, hijacked the desktop wallpaper and lock screen, enforced a logon banner, and disabled the local administrator account across every domain-joined Windows workstation — all without dropping a ransomware binary or encrypting any data. The only ransomware we found in this incident was PAYLOAD sample targeting ESXi on Linux servers. Besides that, data exfiltration was observed originating from the file servers and several additional systems, and was later published on the dark web.
This case is an example of two converging trends that define the 2026 ransomware landscape :
Living-off-the-land abuse of trusted AD infrastructure. Group Policy is a signed, allowlisted, SYSTEM-privileged distribution channel that the majority of endpoint detection and response tools is designed not to inspect. By delivering impact through GPO rather than through malware, the actor sidestepped the entire file- and process-based detection stack.
Encryptionless extortion. Industry telemetry shows extortion-only incidents grow significantly year-on-year. PAYLOAD fits this model; the leverage is operational disruption and the threat of escalation rather than cryptographic denial of data.
We confirmed that no files were encrypted on Windows machines, no malicious binaries were resident on disk, no endpoint persistence was established, and no malicious processes were running at the time of analysis. The entire attack lived inside Active Directory itself. The defensive implication is stark: an organization whose detection strategy depends on catching a ransomware executable would have seen nothing until the first endpoint rebooted and the ransom wallpaper appeared.
In this article, we will describe the GPO attack chain and provide operational advice on how to detect such threats, including detailed remediation recommendations.
Attacks through group policies are nothing new. They can inflict significant, domain-wide damage with multiple malicious capabilities. A Group Policy Object (GPO) is essentially a combination of a Group Policy Container (GPC) in Active Directory and a Group Policy Template (GPT) in SYSVOL. The Group Policy scope depends on whether the GPC is linked to the directory tree at the domain, site, or organization unit (OU) level. A link at the domain root means the policy applies to every computer and user object beneath it. Thus, a GPO compromised at the domain root can affect all in-scope domain users and computers, potentially granting an attacker complete control over the corporate network. What makes GPO abuse even more dangerous is that group policies are processed in a trusted, high-privilege environment, ensuring persistence because endpoint cleanup is not enough to remove them.
We have already discussed GPO architecture and ways it can be compromised in greater detail in an earlier blog post . Other public threat intelligence has also repeatedly documented this technique in ransomware operations. Microsoft observed Ryuk operators distributing ransomware through Group Policy, SYSVOL startup items, and PsExec. LockBit affiliates have been documented modifying SYSVOL Group Policy files, including ScheduledTasks.xml, to support ransomware execution and propagation. BlackCat/ALPHV operators have also abused GPOs to create scheduled tasks and deploy ransomware.
Another notable example of GPO abuse is PAYLOAD ransomware, which weaponizes GPO Preferences and policy settings for pure impact rather than as a launcher for an encryptor. Let’s take a closer look at this attack, which is detailed further below.
During the April 2026 investigation, we managed to reconstruct the attack timeline as outlined below:
Next, we will discuss each of these stages in more detail and share the findings from our incident response activities.
The entry vector was a compromised valid account (MITRE ATT&CK T1078) used to authenticate through the organization’s FortiGate SSL VPN — an external remote service (T1133). Insufficient logging on the FortiGate appliance prevented us from reconstructing how the credential was originally compromised.
Three hypotheses were considered plausible in the context of the attack, in no particular order:
Password spraying or credential stuffing against the SSL VPN portal.
Phishing-led credential harvesting.
Purchase of pre-compromised credentials from an initial access broker (IAB).
Once on the internal network, the actor operated with the compromised security principal’s privileges. Because the account was able to create and link a GPO at the domain root, it held either domain admin privileges or a delegated equivalent (e.g., membership of Group Policy Creator Owners combined with link rights on the domain object).
FortiGate SSL VPN authentication logs and ESXi/virtualization privilege escalation logs were insufficient to reconstruct the lateral movement and privilege escalation chain between initial VPN access and the GPO write privilege level. The most common real-world routes to GPO control — DCSync , Kerberoasting of privileged service accounts, and Pass-the-Hash/Pass-the-Ticket — could not be confirmed or ruled out.
Rather than deploying an encryptor, the actor abused the victim’s Active Directory policy infrastructure, resulting in malicious GPOs being configured and linked at the domain root to deliver the observed impact across domain-joined systems. The two GPOs below constitute the entire offensive toolkit observed.
We performed a Resultant Set of Policy (RSOP) analysis, which helped us list all policy settings on the affected workstations. From these results, we reconstructed the following changes delivered by PAYLOAD:
The PAYLOAD GPO enabled the following actions:
Drop SYSVOL\hello.txt to the desktop and root directories C:\ and D:\ as a read-only README-payload.txt by tampering with the “Group Policy Files” client-side extension (CSE).
Modify the HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ registry key, changing the legalnoticecaption value to “Welcome to Payload!” and the legalnoticetext to the ransom note text through the “Group Policy Registry” CSE.
Set payload.jpg located in the targeted domain controller’s SYSVOL as the lock screen image by altering the personalization policy, and as the wallpaper by altering the desktop policy at the user level.
Revoke administrator rights for the administrator account (locking the account) by editing the Security Settings CSE in the GptTmpl.inf file.
Settings changed by PAYLOAD GPO
This activity was enabled entirely through a legitimate group policy mechanism, meaning there is no malware code for security solutions to look for because the malicious logic is contained within the policy configuration.
A second domain-root-linked GPO, named “win Firewall Off”, disabled Windows Firewall across the domain, private and public profiles on all endpoints (T1562.004). Deployed independently of PAYLOAD, this object degraded host defenses and ensured the actor retained unimpeded network reach to endpoints for any follow-on activity.
Settings changed by win Firewall Off GPO
The most forensically instructive detail is the one-day gap between GPO creation (13 April) and visible impact (14 April). Analysis of Master File Table (MFT) timestamps and the Group Policy History registry key confirmed the policy was written to SYSVOL and cached on endpoints on 13 April. However, computer configuration settings (wallpaper and lock screen machine policy, security settings, firewall disabling) only apply upon reboot or policy refresh — and no endpoint had rebooted in the interim. The attack therefore remained dormant in the GPO cache for one day before detonating en masse when machines were restarted in accordance with standard procedures.
We have to point out here that this delayed policy application is characteristic of GPO-based operations and has two potential consequences for defenders. Firstly, it may grant the actor a quiet window for exfiltration, persistence, or further staging between weaponization and impact. Secondly, it can be used to sever the temporal link between the cause (a GPO-creation event in the directory log) and the effect (mass user-visible disruption occurring at a later time), complicating timeline reconstruction unless directory service auditing is in place.
Initial incident response engagement revealed a number of findings associated with the attack that we share below.
No file encryption A full review of the MFT on affected workstations found no files bearing a .payload extension characteristic to PAYLOAD ransomware and no evidence of bulk renaming or encryption I/O patterns. The attackers’ objectives were operational disruption and extortion via visual impact and access denial.
No endpoint persistence All standard persistence locations were clean: Scheduled tasks — no malicious tasks Run/RunOnce keys — clean Startup folders (user and system) — clean Services — no malicious service installed WMI event subscriptions — none Boot sector/MBR — unmodified The attack’s persistence mechanism is the GPO link itself on the domain controller, with no endpoint-resident component.
Scheduled tasks — no malicious tasks
Run/RunOnce keys — clean
Startup folders (user and system) — clean
Services — no malicious service installed
WMI event subscriptions — none
Boot sector/MBR — unmodified
The attack’s persistence mechanism is the GPO link itself on the domain controller, with no endpoint-resident component.
No active malicious processes Live process and memory analysis revealed no injected threads, process hollowing or anomalous outbound connections.
Registry timeline analysis Group Policy History, Shadow and State registry keys on the workstation recorded the application of PAYLOAD on 13 April: HKLM\…\Group Policy\History\{35378EAC-683F-11D2-A89A-00C04FBBCFA2}\1 HKLM\…\Group Policy\Shadow\{827D319E-6EAC-11D2-A4EA-00C04F79F83A}\0 HKLM\…\Group Policy\State\Machine\GPO-List\7 HKCU\…\Group Policy\History\{7150F9BF-48AD-4da4-A49C-29EF4A8369BA}\1 HKCU\…\Group Policy\State\S-1-5-21-…\Loopback-GPO-List\5 The presence of the “Loopback-GPO-List” entry indicates the GPO was processed in loopback mode , ensuring the user configuration (wallpaper) applied regardless of which user logged on to the machine.
SYSVOL artifacts Two files were staged on the domain controller’s SYSVOL share and served to endpoints through the Files Group Policy Preference CSE: payload.jpg — the ransom image used for both wallpaper and lock screen. hello.txt — the ransom note, distributed to desktops and drive roots as README-payload.txt.
payload.jpg — the ransom image used for both wallpaper and lock screen.
hello.txt — the ransom note, distributed to desktops and drive roots as README-payload.txt.
Because no malicious binary or process exists, the detection logic should focus on the directory service and SYSVOL indicators. Below are the highest-value telemetry sources for identifying the described malicious activity.
Directory service change auditing (DS Access) Enable Advanced Audit Policy → DS Access → Audit Directory Service Changes on all domain controllers and set up alerts for the following events: Event ID Meaning Hunt focus 5137 A directory service object was created The account that created new groupPolicyContainer objects must be an authorized GPO administrator 5136 A directory service object was modified Changes to gPLink on the domain root or sensitive organizational units; changes to gPCMachineExtensionNames/gPCUserExtensionNames/gPCFileSysPath/versionNumber for all GPOs 5141 A directory service object was deleted GPO deletions (relevant for tamper detection and remediation assessment) A gPLink modification at the domain root by a non-standard account is one of the most telling indicators of this attack class.
A gPLink modification at the domain root by a non-standard account is one of the most telling indicators of this attack class.
SYSVOL file integrity monitoring Monitor \\DC.THECOMPANY.local\sysvol\THECOMPANY.local\Policies\ for unexpected files, particularly image files, text files, scripts, ScheduledTasks.xml, and modified registry.pol/GptTmpl.inf files that were created by sources other than legitimate replication.
Endpoint policy application telemetry On endpoints, GPO application is logged in the Group Policy Operational log (Microsoft-Windows-GroupPolicy/Operational) and reflected in the History and Shadow registry keys shown above. A sudden domain-wide change to the applied policy set is a strong post-detonation signal.
Missing 5136 events If the contents of a GPO’s SYSVOL change without a corresponding 5136 event, this can indicate direct SYSVOL/template editing (e.g., via open-source tools such as PowerView or SharpGPOAbuse) that bypasses the normal Group Policy Management Console (GPMC) modification path. While we recommend treating the absence of expected audit events as suspicious, it should be noted that this can be caused by misconfigured auditing.
The Windows endpoint attack described in this report was implemented through malicious Group Policy Objects and did not involve a recovered ransomware executable, resident endpoint malware, confirmed file encryption or active malicious processes at the time of the forensic examination. However, PAYLOAD cryptomalware for Windows does exist, and other sources, including public analysis of its samples, reveal further malicious capabilities of this ransomware that could be used by security teams to enrich detection logic and security policies.
The behaviors documented in this section must therefore be interpreted as family-level capabilities identified through the public reverse engineering of PAYLOAD ransomware samples. They were not confirmed as having executed during the GPO-based incident unless corresponding evidence was identified in the host, memory, process, event-log, or hypervisor.
Public reverse engineering of the PAYLOAD Windows variant reveals an optional event log clearing capability (T1685.005, formerly T1070.001). The ransomware dynamically resolves Windows Event Log APIs, enumerates available event log channels, and clears individual channels.
Implementation artifacts include:
Runtime loading of wevtapi.dll
Enumeration of Security, System, Application, and PowerShell logs, and operational channels
A command-line option controlling whether log clearing is performed
Clearing event logs reduces the availability of records related to process execution, authentication, PowerShell, service control, and system changes. However, it does not necessarily remove events that were already forwarded to a SIEM, Windows Event Collector, EDR backend, or protected log archive.
Windows Security Event ID 1102
Event logging shutdown or failure events
Sudden reductions in event record identifiers
Multiple event channels restarting from low record numbers
Gaps between endpoint and centrally forwarded telemetry
Execution of utilities or APIs associated with log management
Direct access to EVTX files (Windows Event Log files) under the Windows event log directory
We should note that these indicators can’t be interpreted on their own. For instance, Event ID 1102 should be correlated with a number of aggravating factors, such as:
Event ID 4688 or Sysmon Event ID 1 for process creation
Event ID 4624 for the associated administrative logon
PowerShell operational logging
Windows Event Forwarding records
Privileged access management activity
At the same time, the absence of Event ID 1102 does not prove that log clearing did not occur. Direct deletion, truncation, service impairment, or an incomplete audit configuration may produce different evidence.
PAYLOAD analysis reveals that the Windows ransomware variant contains logic that targets security processes and services (T1685 and T1489). This capability is intended to stop security products, backup software, database services, and applications that may lock files targeted for encryption. Process and service termination serves several objectives:
Reduce endpoint detection and response visibility.
Release file handles so data can be modified.
Interrupt backup and recovery services.
Prevent databases and enterprise applications from protecting active data.
Reduce interference with encryption operations.
Security agent services changing from running to stopped
Event ID 7036 service state changes
Event ID 7040 service start type changes
Event ID 4688 or Sysmon Event ID 1 for service control utilities
Sysmon Event ID 5 for terminated processes
EDR health degradation affecting many endpoints
Repeated termination attempts against security or backup processes
Execution of dedicated process killing utilities
Public PAYLOAD sample analysis reports the deletion of Windows Volume Shadow Copies before encryption (T1490). This behavior removes local restore points and reduces the victim’s ability to recover files without external backups.
Recovery inhibition is broader than VSS deletion and may include multiple other malicious techniques, including the following:
Deleting shadow copies, backup catalogs, and hypervisor snapshots
Disabling recovery services
Modifying boot recovery settings
Compromising backup management platforms
Deleting or encrypting backup repositories
In the PAYLOAD Windows sample that is proven to perform encryption, VSS deletion is confirmed to have taken place before encryption. A broader compromise of the backup platform was not established in the investigated incident.
Execution of shadow copy management utilities
Backup catalog deletion attempts
Recovery configuration changes
Backup service termination
Mass snapshot deletions
Backup administrator logons outside normal maintenance windows
Backup retention or immutability changes
Backup jobs failing immediately before disruptive activity
Above, we discussed the techniques specific to PAYLOAD ransomware. In this section, we’ll review other common ransomware techniques, such as BYOVD abuse and ESXi policy weakening, that remain relevant risks in the ransomware ecosystem. However, these techniques should not be attributed to this incident without supporting driver load, process, memory, ESXi, vCenter, or backup platform telemetry. We describe these techniques below as they may prove useful in other ransomware-related forensic investigations.
The examples used in this section are therefore ecosystem-relevant: they are commonly observed in ransomware operations but not conclusively attributed to the analyzed PAYLOAD samples.
Event Tracing for Windows (ETW) is a kernel-supported tracing architecture used by Windows components, diagnostic utilities, security products, and endpoint monitoring systems.
Although we didn’t encounter this technique in our case, some ransomware families can patch ETW-related functions inside the ransomware process (T1685, formerly T1562.001). The reported routine changes the memory protection of code pages, overwrites the beginning of selected ETW functions so they return without producing events, restores the original protection, and refreshes the instruction cache.
Reported target functions include EtwEventWrite, EtwEventWriteFull, EtwEventWriteTransfer, and EtwRegister.
This modification applies to the process-local mapping of ntdll.dll. It does not disable ETW globally across Windows, but it can reduce the telemetry generated by the modified process.
Writable or recently modified executable pages within ntdll.dll
Memory protection changes affecting ETW function addresses
In-memory code differing from the corresponding clean DLL on disk
EDR memory tampering alerts
Unexpected calls to memory protection APIs followed by telemetry silence
Process execution visible in network or filesystem telemetry but absent from expected ETW-derived sources
Inconsistent telemetry between EDR, Sysmon, Windows Event Logs, and network monitoring
It should be noted that telemetry gaps are not conclusive evidence of ETW patching. Other factors include agent upgrades, network outages, endpoint shutdowns, SIEM ingestion failures, collector backpressure, and filtering or licensing changes.
Memory acquisition is the strongest validation source when process-local ETW patching is suspected.
Bring Your Own Vulnerable Driver (BYOVD) involves introducing or abusing a legitimately signed but vulnerable kernel driver (T1068 and T1685). The attacker exploits the driver’s exposed functionality to gain kernel-level capabilities, modify protected memory, terminate security processes, remove security callbacks, or bypass operating system security controls.
BYOVD is highly relevant to contemporary ransomware operations. However, the reviewed public PAYLOAD analyses do not provide sufficient evidence to conclude that BYOVD is an intrinsic PAYLOAD capability.
It should therefore be presented as an ecosystem-relevant technique rather than a confirmed PAYLOAD feature.
Unexpected .sys files written to user-writable or temporary directories
New kernel driver services
Driver hashes matching Microsoft or community vulnerable driver blocklists
Invalid, revoked, expired, or unusual driver signatures
Driver load followed by EDR termination
New privileged processes immediately following driver loading
Code Integrity or Defender alerts
Service creation events referencing driver files
Ransomware operators are increasingly targeting ESXi and vCenter because compromising the virtualization layer provides access to many business-critical virtual machines.
Public research typically describes operators performing the following activities (T1685, T1490 and T1489):
Enabling SSH on ESXi hosts
Changing root passwords
Disabling execInstalledOnly
Modifying lockdown mode exceptions
Stopping virtual machines
Deleting snapshots and backups
Changing host firewall policies
Copying custom ransomware binaries to hypervisors
On the target organization’s Linux servers we saw an ESXi PAYLOAD variant, which makes this behavior operationally relevant. Nevertheless, the reviewed evidence does not indicate that PAYLOAD operators used any of these policy-weakening actions in the investigated incident.
Unexpected ESXi SSH enablement
Changes to execInstalledOnly
Secure Boot enforcement changes
Lockdown mode configuration changes
Root password changes
New or unusual administrator accounts
Bulk VM shutdown activity
Bulk snapshot deletion
New binaries in datastore or temporary paths
vCenter tasks originating from unexpected accounts or systems
Missing or disabled remote syslog forwarding
To contain the described threat and limit possible damage, several remediation steps should be taken. Below, we recommend a four-phase remediation approach for containing this threat and restoring the affected environment.
When dealing with PAYLOAD GPO, the first priority of the remediation plan should be to remove the source GPOs. Until this is done, endpoint cleanup is ineffective because the next policy refresh re-infects cleaned machines.
The immediate domain controller actions to be taken are:
Delete PAYLOAD GPO. Remove {C897F2C7-C2AC-4E6F-BF48-58036FF29E79} via GPMC.
Delete or revert win Firewall Off GPO. Remove {22099AD2-E062-4F56-B574-5099BBA4E7A6}.
Clean SYSVOL. Delete jpg and hello.txt from \\DC.THECOMPANY.local\sysvol\THECOMPANY.local\.
Rotate credentials. Reset the compromised account; audit all privileged accounts and group memberships for unauthorized changes; rotate krbtgt twice if domain admin compromise is confirmed.
Force refresh. Perform gpupdate /force across endpoints after deletion; re-enable local administrator and firewall via clean policy.
Adopt the AD tiered administration model and confine domain admins to Tier 0 with no interactive logon to workstations and member servers.
Separate GPO creation from GPO linking rights, and grant both only to a dedicated, audited administrator role.
Enable GPO change auditing (Event IDs 5136, 5137, 5141) and forward to a SIEM.
Monitor SYSVOL with file integrity tooling.
Enforce phishing-resistant MFA on all VPN and remote access entry points.
Deploy Windows LAPS to generate unique, rotated local administrator passwords.
Enable Credential Guard to protect LSASS-resident secrets.
Adopt Privileged Access Workstations (PAW) for all administration.
Implement just-in-time elevation through Privileged Identity Management (PIM) for domain admin.
SIEM rule: GPO creation or domain-root gPLink change by a non-standard account.
SIEM rule: file creation events under SYSVOL from non-replication sources.
Implement enhanced, centrally collected FortiGate SSL VPN logging (auth events, session detail, source IP geolocation, impossible travel check) and detailed perimeter monitoring.
Deploy a canary GPO whose application anywhere signals attacker GPO write access.
PAYLOAD demonstrates a maturing tactic of turning the victim’s own trusted infrastructure into a weapon. By weaponizing Group Policy, the actor achieved a domain-wide impact without a single malicious binary on any endpoint, evaded file- and process-based detection entirely, and caused organization-wide disruption within seconds of the first reboot.
The absence of encryption is the most strategically significant finding and is consistent with the 2026 trend toward encryptionless extortion . At Kaspersky GERT, we assess with moderate confidence that the missing encryption reflects one of two scenarios: (1) a deliberate decision to stay below the irreversible data destruction threshold while preserving the option of a follow-on encryption phase, or (2) an operation interrupted before full execution.
The absence of encrypted files must not be mistaken for the absence of a serious compromise — the most critical impact lies in the actor gaining domain admin-level control. This incident proves that a threat actor with domain admin access and a working knowledge of group policy internals can inflict domain-wide disruption equivalent to a ransomware attack without writing a single malicious file to any endpoint.
Detection strategies anchored solely in file- or process-based indicators are blind to this attack class. Effective controls include directory service change auditing, SYSVOL integrity monitoring, and privileged access governance, which allow for GPO protection.
Kaspersky security solutions effectively detect the described malicious activity at various stages of the attack. Possible detection scenarios are listed below. To protect organizations that use our Kaspersky SIEM system, we have prepared a package of correlation rules designed to help detect this type of malicious activity. The rules are now available for customers to download from the SIEM repository; the package name is: [OOTB] Group policy hijacked: PAYLOAD ransomware – ENG.
The “Group policy hijacked: PAYLOAD ransomware” package contains rules that detect suspicious file creation or modification in the SYSVOL shared folder on a domain controller, as well as changes to critical attributes and settings of domain group policies. Some rules may require adjustment if they trigger in response to legitimate activity, such as synchronization between domain controllers or the configuration of a new group policy.
To ensure the detection rules function correctly, verify that events from Windows systems are being received in full, including events with the following identifiers: Sysmon: 11, Security — 4663, 5136, 4657.
We also recommend applying the following rules available in the repository to detect all attack stages.
Detection of Windows Event Log clearing to cover up traces of an attack: R050_03_Windows Event Log was cleared
Detection of suspicious access to the LSASS process, which may indicate attempts to dump credentials: R262_Suspicious access to the LSASS process
Detection of the Volume Shadow Copy service being started, which is used to create shadow copies before deleting them: R231_20_Running the Volume Shadow Copy service
Detection of shadow copy deletion: R321_Shadow copy deletion
Detection of Windows Defender disablement: R076_01_Windows Defender Antivirus was disabled
Detection of attempts to disable or modify the system firewall: R240_03_Disabling system firewall via the registry
Detection of a service installation from a non-system folder, which may indicate malware persistence techniques: R281_01_Installation of a service from a non-system folder
For the rules in this list to function correctly, it is necessary to configure Security event auditing for event IDs 4663, 5136, 4657, 7036, and 1102.
In addition to the SIEM system, when audit settings are configured correctly, the process of creating, modifying, and deleting GPOs generates a large number of characteristic artifacts on the domain controller, enabling Kaspersky Endpoint Detection and Response Expert to promptly alert the user to anomalies in the infrastructure.
The creation of a new GPO is covered by the gpo_creation rule, which triggers in response to the corresponding event in the infrastructure. Changes to existing policies are detected by the following rules:
The setting_the_gpcmachineextensionname_attribute rule detects changes to the gPCMachineExtensionNames attribute.
The setting_the_gpcfilesyspath_attribute rule detects the use of the gPCFileSysPath attribute of a Group Policy Object, which specifies the path to the GPO’s contents in SYSVOL.
The broader rule setting_the_grouppolicycontainer_class detects a change to the groupPolicyContainer class.
GPO deletion is covered by the gpo_deletion rule.
In the next major version update of Kaspersky EDR Expert, a new event type, GPO, will be introduced, allowing users to track changes to Group Policy Objects.
For information security officers, GPO events will serve as an additional source of context when investigating activity in Active Directory and will help detect changes that could affect the configuration, access rights, and security of endpoints before a potentially malicious policy is deployed.
GPOs PAYLOAD ransomware GPO: {C897F2C7-C2AC-4E6F-BF48-58036FF29E79} win Firewall Off GPO: {22099AD2-E062-4F56-B574-5099BBA4E7A6}
File names and MD5 hashes payload.jpg: Ransom wallpaper and lock screen image (SYSVOL) hello.txt: Ransom note source (SYSVOL) README-payload.txt: Ransom note dropped to desktops and drive roots killer.exe ( 0108656A3E1ADE6CA4F21B084F5E1208 ): process killer tool kill.exe ( BEA5E267F24D7DA59F6821BFFDBFF293 ): process killer tool
IP addresses 37.19.210[.]12 146.70.117[.]239 149.102.229[.]154 104.164.55[.]46 104.28.162[.]228 104.28.163[.]162 64.190.76[.]14 192.42.116[.]50 192.42.116[.]12 192.42.116[.]56 192.42.116[.]97 192.42.116[.]52
Registry keys HKLM\...\Policies\System\legalnoticecaption = Welcome to Payload!
SYSVOL path \\DC.THECOMPANY.local\sysvol\THECOMPANY.local\payload.jpg
Event IDs 5137: GPO object creation on DC — review creator account 5136: GPO attribute modification — watch gPLink at domain root
Group Policy hijacked: PAYLOAD ransomware weaponizes Active Directory GPO
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组策略作为攻击面
防火墙关闭 GPO
延迟一天引爆
检测工程
反取证和恢复抑制能力
已确认的有效载荷系列功能
Windows事件日志清除
安全流程和服务终止
VSS删除、备份和恢复抑制
与生态系统相关的勒索软件技术
ETW抑制和内存修补
易受攻击的签名驱动程序滥用,自带设备 (BYOVD)
ESXi 安全策略减弱
第一阶段——域控制器操作(首先执行)
第二阶段——Active Directory 和 GPO 加固
第三阶段——凭证和访问安全强化
第四阶段——检测和监测
卡巴斯基解决方案的检测
MITRE ATT&CK 映射
妥协的迹象
2026年4月,卡巴斯基全球紧急响应团队 (GERT) 响应了中东一家制造企业的安全事件。攻击者获得了该企业 Active Directory 环境的域管理员权限,并创建了一个名为 PAYLOAD 的恶意组策略对象 (GPO),将其链接到域根目录。攻击者通过该 GPO 发送勒索信、劫持桌面壁纸和锁屏、强制显示登录横幅,并禁用了所有已加入域的 Windows 工作站的本地管理员帐户——所有这些都未投放勒索软件二进制文件或加密任何数据。我们在此次事件中发现的唯一勒索软件是针对 Linux 服务器上 ESXi 的 PAYLOAD 样本。此外,我们还观察到数据从文件服务器和其他几个系统中泄露,相关数据随后被发布到暗网上。
本案例体现了定义 2026 年勒索软件格局的两大融合趋势:
攻击者利用可信的 AD 基础架构进行“借力打力”式的滥用。组策略 (GPO) 是一种经过签名、列入白名单且拥有 SYSTEM 权限的分发渠道,而大多数端点检测和响应工具的设计初衷并非对其进行检查。攻击者通过 GPO 而非恶意软件来施加影响,从而绕过了整个基于文件和进程的检测机制。
无加密勒索。行业遥测数据显示,仅进行勒索的事件逐年显著增长。PAYLOAD 符合这种模式;其杠杆作用在于运营中断和升级威胁,而非加密数据拒绝。
我们确认,在分析时,Windows 机器上没有文件被加密,磁盘上没有恶意二进制文件,没有建立终端持久化,也没有恶意进程正在运行。整个攻击过程都发生在 Active Directory 内部。这带来的防御后果非常严重:如果组织的检测策略依赖于捕获勒索软件可执行文件,那么在第一个终端重启并出现勒索壁纸之前,他们将一无所知。
在本文中,我们将描述 GPO 攻击链,并提供有关如何检测此类威胁的操作建议,包括详细的补救建议。
利用组策略发起的攻击并非新鲜事。它们能够造成严重的域级破坏,并具备多种恶意功能。组策略对象 (GPO) 本质上是 Active Directory 中的组策略容器 (GPC) 和 SYSVOL 中的组策略模板 (GPT) 的组合。组策略的作用范围取决于 GPC 是否链接到域、站点或组织单元 (OU) 级别的目录树。如果链接到域根目录,则该策略将应用于其下的所有计算机和用户对象。因此,如果域根目录的 GPO 遭到入侵,则会影响所有作用域内的用户和计算机,攻击者甚至可能完全控制企业网络。更危险的是,组策略在受信任的高权限环境中处理,因此即使进行终端清理也无法将其彻底清除,从而确保了策略的持久性。
我们此前已在一篇博文中详细讨论过 GPO 架构及其可能被攻破的方式。其他公开的威胁情报也多次记录了勒索软件攻击中出现的此类技术。微软观察到 Ryuk 勒索软件运营者通过组策略、SYSVOL 启动项和 PsExec 分发勒索软件。LockBit 的关联组织也被记录到修改 SYSVOL 组策略文件(包括 ScheduledTasks.xml)以支持勒索软件的执行和传播。BlackCat/ALPHV 的运营者也曾滥用 GPO 创建计划任务并部署勒索软件。
另一个值得注意的 GPO 滥用案例是 PAYLOAD 勒索软件,它利用 GPO 首选项和策略设置进行攻击,其目的并非作为加密程序的启动器,而是单纯地造成破坏。让我们更深入地了解一下这种攻击,详情如下。
在 2026 年 4 月的调查中,我们成功重建了攻击时间线,如下所示:
接下来,我们将更详细地讨论这些阶段,并分享我们事件响应活动的调查结果。
攻击入口点是一个被盗用的有效账户(MITRE ATT&CK T1078),该账户用于通过组织的 FortiGate SSL VPN(一项外部远程服务,T1133)进行身份验证。由于 FortiGate 设备上的日志记录不足,我们无法还原凭证最初是如何被盗用的。
在本次袭击事件中,有三种假设被认为是合理的,以下假设不分先后:
针对 SSL VPN 门户的密码喷洒或凭证填充攻击。
通过网络钓鱼窃取凭证。
从初始访问代理(IAB)处购买预先泄露的凭证。
一旦进入内部网络,攻击者便以被入侵的安全主体的权限进行操作。由于该帐户能够在域根目录创建和链接 GPO,因此它拥有域管理员权限或委派的等效权限(例如,组策略创建者所有者成员身份以及对域对象的链接权限)。
FortiGate SSL VPN 身份验证日志和 ESXi/虚拟化权限提升日志不足以重构从初始 VPN 访问到 GPO 写入权限级别之间的横向移动和权限提升链。最常见的几种实际 GPO 控制手段——DCSync、特权服务帐户的 Kerberoasting 攻击以及哈希传递/票据传递——均无法得到证实或排除。
攻击者并未部署加密器,而是滥用了受害者的 Active Directory 策略基础架构,导致恶意 GPO 在域根目录配置并链接,从而对已加入域的系统造成影响。以下两个 GPO 构成了所观察到的全部攻击工具包。
我们执行了策略结果集 (RSOP) 分析,这有助于我们列出受影响工作站上的所有策略设置。根据这些结果,我们重建了 PAYLOAD 带来的以下更改:
有效载荷 GPO 启用了以下操作:
通过修改“组策略文件”客户端扩展 (CSE),将 SYSVOL\hello.txt 作为只读的 README-payload.txt 文件放到桌面和根目录 C:\ 和 D:\ 中。
修改 HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ 注册表项,将 legalnoticecaption 值更改为“欢迎使用 Payload!”,并将 legalnoticetext 更改为勒索信文本,方法是通过“组策略注册表”CSE。
通过更改个性化策略,将位于目标域控制器 SYSVOL 中的 payload.jpg 设置为锁屏图像;通过更改用户级别的桌面策略,将其设置为壁纸。
通过编辑 GptTmpl.inf 文件中的安全设置 CSE 来撤销管理员帐户的管理员权限(锁定帐户)。
有效载荷组策略更改了设置
这项活动完全是通过合法的组策略机制实现的,这意味着安全解决方案无需查找恶意软件代码,因为恶意逻辑包含在策略配置中。
第二个与域根目录关联的组策略对象 (GPO),名为“win Firewall Off”,禁用了域内所有端点的 Windows 防火墙,包括专用和公共配置文件 (T1562.004)。该对象独立于 PAYLOAD 部署,降低了主机防御能力,并确保攻击者能够畅通无阻地访问端点,以便进行后续活动。
通过 Windows 防火墙关闭 GPO 更改了设置
最具取证意义的细节是组策略对象 (GPO) 创建日期(4 月 13 日)与可见影响日期(4 月 14 日)之间仅相隔一天。对主文件表 (MFT) 时间戳和组策略历史记录注册表项的分析证实,该策略已于 4 月 13 日写入 SYSVOL 并缓存在终端设备上。然而,计算机配置设置(例如壁纸和锁屏策略、安全设置、防火墙禁用)仅在重启或策略刷新后生效——而在此期间没有任何终端设备重启。因此,该攻击在 GPO 缓存中潜伏了一天,直到计算机按照标准流程重启后才大规模爆发。
我们必须在此指出,这种策略应用延迟是基于组策略对象 (GPO) 的操作的典型特征,并且可能对防御者造成两种后果。首先,它可能为攻击者提供一个安全窗口,使其能够在武器化和攻击之间进行数据窃取、持久化或进一步的部署。其次,它可能被用来切断原因(目录日志中的 GPO 创建事件)和结果(稍后发生的大规模用户可见的干扰)之间的时间联系,除非部署了目录服务审计机制,否则将使时间线重建变得复杂。
初步事件响应工作揭示了与此次攻击相关的若干发现,我们将在下面分享。
未发现文件加密。对受影响工作站上的主文件表 (MFT) 进行全面检查后发现,没有文件带有 PAYLOAD 勒索软件特有的 .payload 扩展名,也没有发现批量重命名或加密 I/O 模式的迹象。攻击者的目标是通过视觉冲击和拒绝访问来扰乱运营并进行勒索。
无终端持久性 所有标准持久性位置均干净: 计划任务 — 无恶意任务 Run/RunOnce 键 — 干净 启动文件夹(用户和系统) — 干净 服务 — 未安装恶意服务 WMI 事件订阅 — 无 引导扇区/MBR — 未修改 攻击的持久性机制是域控制器上的 GPO 链接本身,没有终端驻留组件。
计划任务——无恶意任务
Run/RunOnce 键 — 清理
启动文件夹(用户和系统)— 清理
服务 — 未安装恶意服务
WMI 活动订阅 — 无
引导扇区/MBR — 未修改
该攻击的持久化机制是域控制器上的 GPO 链接本身,没有终端驻留组件。
未发现活跃的恶意进程。实时进程和内存分析显示,没有注入线程、进程空心化或异常的出站连接。
注册表时间线分析显示,工作站上的组策略历史记录、影子策略和状态注册表项记录了 4 月 13 日 PAYLOAD 的应用:HKLM\…\Group Policy\History\{35378EAC-683F-11D2-A89A-00C04FBBCFA2}\1 HKLM\…\Group Policy\Shadow\{827D319E-6EAC-11D2-A4EA-00C04F79F83A}\0 HKLM\…\Group Policy\State\Machine\GPO-List\7 HKCU\…\Group Policy\History\{7150F9BF-48AD-4da4-A49C-29EF4A8369BA}\1 HKCU\…\Group Policy\State\S-1-5-21-…\Loopback-GPO-List\5 “Loopback-GPO-List” 条目的存在表明 GPO 已应用。以环回模式处理,确保无论哪个用户登录到机器,都能应用用户配置(壁纸)。
SYSVOL 工件:两个文件被暂存在域控制器的 SYSVOL 共享中,并通过文件组策略首选项 CSE 提供给端点:payload.jpg — 用作壁纸和锁屏的勒索图片。hello.txt — 勒索信息,以 README-payload.txt 的形式分发到桌面和驱动器根目录。
payload.jpg — 用作壁纸和锁屏的勒索图片。
hello.txt — 勒索信,以 README-payload.txt 的形式分发到桌面和驱动器根目录。
由于不存在恶意二进制文件或进程,检测逻辑应重点关注目录服务和 SYSVOL 指标。以下是用于识别所述恶意活动的最有价值的遥测数据源。
目录服务变更审核(DS 访问)启用高级审核策略 → DS 访问 → 审核所有域控制器上的目录服务变更,并为以下事件设置警报:事件 ID 含义 追踪重点 5137 创建了目录服务对象 创建新 groupPolicyContainer 对象的帐户必须是授权的 GPO 管理员 5136 修改了目录服务对象 对域根或敏感组织单元上的 gPLink 进行了更改;所有 GPO 的 gPCMachineExtensionNames/gPCUserExtensionNames/gPCFileSysPath/versionNumber 进行了更改 5141 删除了目录服务对象 GPO 删除(与篡改检测和修复评估相关) 非标准帐户对域根上的 gPLink 进行的修改是此类攻击最明显的指标之一。
非标准帐户对域根目录的 gPLink 修改是此类攻击最明显的特征之一。
SYSVOL 文件完整性监控 监控 \\DC.THECOMPANY.local\sysvol\THECOMPANY.local\Policies\ 中是否存在意外文件,特别是图像文件、文本文件、脚本、ScheduledTasks.xml 和由合法复制以外的源创建的已修改 registry.pol/GptTmpl.inf 文件。
端点策略应用遥测:在端点上,GPO 应用会记录在组策略操作日志 (Microsoft-Windows-GroupPolicy/Operational) 中,并反映在上面显示的历史记录和影子注册表项中。域范围内应用策略集的突然更改是爆炸后的一个强烈信号。
缺少 5136 事件:如果 GPO 的 SYSVOL 内容发生更改,但没有相应的 5136 事件,则可能表明有人直接编辑了 SYSVOL/模板(例如,通过 PowerView 或 SharpGPOAbuse 等开源工具),从而绕过了正常的组策略管理控制台 (GPMC) 修改路径。虽然我们建议将预期审核事件的缺失视为可疑情况,但需要注意的是,这也可能是由于审核配置错误造成的。
本报告所述的 Windows 端点攻击是通过恶意组策略对象实施的,在取证检查时,并未发现已恢复的勒索软件可执行文件、驻留端点恶意软件、已确认的文件加密或活动的恶意进程。然而,针对 Windows 系统的 PAYLOAD 加密恶意软件确实存在,其他来源(包括对其样本的公开分析)揭示了该勒索软件的更多恶意功能,安全团队可以利用这些功能来增强检测逻辑和安全策略。
因此,本节记录的行为必须被解释为通过对 PAYLOAD 勒索软件样本进行公开逆向工程而识别出的家族级功能。除非在主机、内存、进程、事件日志或虚拟机管理程序中发现相应的证据,否则不能确认这些功能在基于 GPO 的事件中执行过。
对 PAYLOAD Windows 变种的公开逆向工程揭示了一个可选的事件日志清除功能(T1685.005,原 T1070.001)。该勒索软件能够动态解析 Windows 事件日志 API,枚举可用的事件日志通道,并清除各个通道。
实现成果包括:
wevtapi.dll 运行时加载
枚举安全日志、系统日志、应用程序日志、PowerShell 日志和操作通道
控制是否执行日志清除操作的命令行选项
清除事件日志会减少与进程执行、身份验证、PowerShell、服务控制和系统更改相关的记录的可用性。但是,它不一定会删除已转发到 SIEM、Windows 事件收集器、EDR 后端或受保护日志存档的事件。
Windows 安全事件 ID 1102
事件日志记录关闭或故障事件
事件记录标识符突然减少
多个事件通道从低谷期重新启动
端点遥测与集中转发遥测之间的差距
执行与日志管理相关的实用程序或 API
直接访问 Windows 事件日志目录下的 EVTX 文件(Windows 事件日志文件)
需要注意的是,这些指标不能单独解读。例如,事件 ID 1102 应与许多加剧因素相关联,例如:
事件 ID 4688 或 Sysmon 事件 ID 1,表示进程创建
关联的管理员登录事件 ID 为 4624
PowerShell 操作日志记录
Windows 事件转发记录
特权访问管理活动
同时,缺少事件 ID 1102 并不能证明日志清除操作未发生。直接删除、截断、服务中断或审计配置不完整都可能导致不同的结果。
有效载荷分析显示,该 Windows 勒索软件变种包含针对安全进程和服务(T1685 和 T1489)的逻辑。此功能旨在阻止安全产品、备份软件、数据库服务以及可能锁定加密目标文件的应用程序运行。进程和服务终止有以下几个目的:
降低端点检测和响应可见性。
发布文件句柄,以便可以修改数据。
中断备份和恢复服务。
阻止数据库和企业应用程序保护活动数据。
减少对加密操作的干扰。
安全代理服务已从运行状态更改为停止状态
事件 ID 7036 服务状态变更
事件 ID 7040 服务启动类型变更
服务控制实用程序的事件 ID 4688 或 Sysmon 事件 ID 1
Sysmon 事件 ID 5,表示进程已终止
EDR 健康恶化影响多个终点
反复尝试终止安全或备份进程
执行专用流程终止实用程序
公开的 PAYLOAD 样本分析报告显示,加密前会删除 Windows 卷影副本 (T1490)。此行为会移除本地还原点,降低受害者在没有外部备份的情况下恢复文件的能力。
恢复抑制的范围比 VSS 删除更广,可能包括多种其他恶意技术,包括以下几种:
删除卷影副本、备份目录和虚拟机管理程序快照
禁用恢复服务
修改启动恢复设置
损害备份管理平台
删除或加密备份存储库
在已证实可执行加密操作的 PAYLOAD Windows 样本中,已确认 VSS 删除操作发生在加密之前。本次调查事件并未发现备份平台遭到更广泛的入侵。
执行卷影副本管理实用程序
尝试删除备份目录
恢复配置更改
备份服务终止
批量删除快照
备份管理员在正常维护窗口之外登录
备份保留或不可篡改变更
备份作业在中断活动发生前立即失败
上文我们讨论了 PAYLOAD 勒索软件特有的技术。本节将回顾其他常见的勒索软件技术,例如 BYOVD 滥用和 ESXi 策略削弱,这些技术在勒索软件生态系统中仍然是相关的风险。但是,如果没有驱动程序负载、进程、内存、ESXi、vCenter 或备份平台遥测数据的支持,就不能将这些技术归因于本次事件。我们将在下文中描述这些技术,因为它们可能对其他勒索软件相关的取证调查有所帮助。
因此,本节中使用的示例与生态系统相关:它们常见于勒索软件操作中,但不能确凿地归因于所分析的有效载荷样本。
Windows 事件跟踪 (ETW) 是一种内核支持的跟踪架构,供 Windows 组件、诊断实用程序、安全产品和端点监控系统使用。
虽然我们此次并未遇到这种技术,但某些勒索软件家族可以修改勒索软件进程内部与 ETW 相关的函数(T1685,原 T1562.001)。据报道,该例程会更改代码页的内存保护,覆盖选定 ETW 函数的开头部分使其在不产生事件的情况下返回,恢复原始保护,并刷新指令缓存。
报告的目标函数包括 EtwEventWrite、EtwEventWriteFull、EtwEventWriteTransfer 和 EtwRegister。
此修改适用于 ntdll.dll 的进程本地映射。它不会在 Windows 系统中全局禁用 ETW,但可以减少修改后的进程生成的遥测数据。
ntdll.dll 中的可写或最近修改的可执行页
影响 ETW 函数地址的内存保护变更
内存中的代码与磁盘上对应的干净 DLL 不同
EDR 内存篡改警报
意外调用内存保护 API 后,遥测数据出现静默。
进程执行情况在网络或文件系统遥测数据中可见,但在预期的 ETW 衍生来源中却未见踪迹。
EDR、Sysmon、Windows 事件日志和网络监控之间的遥测数据不一致
需要注意的是,遥测数据缺失并不能作为ETW补丁的确凿证据。其他因素包括代理升级、网络中断、终端关闭、SIEM数据采集失败、收集器反压以及过滤或许可变更。
当怀疑存在进程本地 ETW 修补时,内存获取是最有力的验证来源。
自带漏洞驱动程序 (BYOVD) 指的是引入或滥用合法签名但存在漏洞的内核驱动程序(T1068 和 T1685)。攻击者利用该驱动程序暴露的功能来获取内核级权限、修改受保护的内存、终止安全进程、移除安全回调或绕过操作系统安全控制。
BYOVD 与当代勒索软件攻击密切相关。然而,已审查的公开 PAYLOAD 分析并未提供充分证据证明 BYOVD 是 PAYLOAD 的固有功能。
因此,它应该被视为一种与生态系统相关的技术,而不是一个已确认的有效载荷功能。
意外的 .sys 文件被写入用户可写目录或临时目录
新内核驱动程序服务
驱动程序哈希值与微软或社区的易受攻击驱动程序黑名单相匹配
无效、已撤销、已过期或异常的驾驶员签名
驱动程序负载随后是 EDR 终止
驱动程序加载后立即创建新的特权进程
代码完整性或 Defender 警报
引用驱动程序文件的服务创建事件
勒索软件运营者越来越多地将目标对准 ESXi 和 vCenter,因为攻破虚拟化层可以访问许多对业务至关重要的虚拟机。
公共研究通常描述操作人员执行以下活动(T1685、T1490 和 T1489):
在 ESXi 主机上启用 SSH
更改root密码
禁用 execInstalledOnly
修改封锁模式例外情况
停止虚拟机
删除快照和备份
更改主机防火墙策略
将自定义勒索软件二进制文件复制到虚拟机管理程序
我们在目标组织的 Linux 服务器上发现了一种 ESXi PAYLOAD 变种,这使得该行为具有实际操作意义。然而,审查的证据并未表明 PAYLOAD 操作员在本次调查事件中使用了任何此类削弱策略的操作。
意外启用 ESXi SSH
对 execInstalledOnly 的更改
安全启动强制执行变更
锁定模式配置变更
Root密码更改
新的或不寻常的管理员帐户
批量虚拟机关闭活动
批量删除快照
数据存储或临时路径中的新二进制文件
vCenter 任务源自意外的帐户或系统
远程系统日志转发缺失或已禁用
为遏制上述威胁并减少可能造成的损害,应采取若干补救措施。以下,我们推荐一种分四个阶段的补救方法,用于遏制该威胁并恢复受影响的环境。
处理 PAYLOAD GPO 时,补救计划的首要任务应该是移除源 GPO。否则,端点清理将无效,因为下次策略刷新会再次感染已清理的计算机。
域控制器应立即采取的措施是:
删除 PAYLOAD GPO。通过 GPMC 删除 {C897F2C7-C2AC-4E6F-BF48-58036FF29E79}。
删除或还原 Windows 防火墙关闭 GPO。移除 {22099AD2-E062-4F56-B574-5099BBA4E7A6}。
清理 SYSVOL。从 \\DC.THECOMPANY.local\sysvol\THECOMPANY.local\ 中删除 jpg 和 hello.txt。
轮换凭据。重置被盗帐户;审核所有特权帐户和组成员身份是否存在未经授权的更改;如果确认域管理员帐户已被盗用,则将 krbtgt 帐户轮换两次。
强制刷新。删除后,在所有端点上执行 gpupdate /force 命令;通过清理策略重新启用本地管理员和防火墙。
采用 AD 分层管理模型,并将域管理员限制在第 0 层,不允许其交互式登录到工作站和成员服务器。
将 GPO 创建权限与 GPO 链接权限分开,并且只授予经过审核的专用管理员角色这两项权限。
启用 GPO 更改审核(事件 ID 5136、5137、5141)并转发到 SIEM。
使用文件完整性工具监控 SYSVOL。
在所有 VPN 和远程访问入口点强制执行防钓鱼的多因素身份验证。
部署 Windows LAPS 以生成唯一的、轮换的本地管理员密码。
启用凭证保护以保护 LSASS 驻留的密钥。
所有管理工作均采用特权访问工作站 (PAW)。
通过特权身份管理 (PIM) 为域管理员实现即时提升权限。
SIEM 规则:非标准帐户创建 GPO 或更改域根 gPLink。
SIEM 规则:SYSVOL 下来自非复制源的文件创建事件。
实施增强的、集中收集的 FortiGate SSL VPN 日志记录(身份验证事件、会话详细信息、源 IP 地理位置、不可能的旅行检查)和详细的边界监控。
部署一个金丝雀 GPO,该 GPO 的应用会在任何地方发出攻击者 GPO 写入权限的信号。
PAYLOAD 展示了一种日趋成熟的攻击策略,即利用受害者自身可信的基础设施作为攻击武器。攻击者通过利用组策略,无需在任何终端上部署任何恶意二进制文件,即可实现全域范围的影响,完全绕过了基于文件和进程的检测,并在首次重启后的几秒钟内造成组织范围内的瘫痪。
加密的缺失是最具战略意义的发现,这与2026年无加密勒索的趋势相符。卡巴斯基GERT团队以中等置信度评估认为,加密缺失反映了以下两种情况之一:(1)故意将数据量控制在不可逆数据销毁阈值以下,同时保留后续加密阶段的选择;(2)操作在完全执行前被中断。
不应将未发现加密文件与未造成严重安全漏洞混为一谈——最关键的影响在于攻击者获得了域管理员级别的控制权限。此次事件证明,拥有域管理员权限并熟悉组策略内部机制的攻击者,无需向任何终端写入任何恶意文件,即可造成相当于勒索软件攻击的全域破坏。
仅依赖文件或进程指标的检测策略无法检测到此类攻击。有效的控制措施包括目录服务变更审计、SYSVOL完整性监控和特权访问治理,这些措施可以实现组策略对象 (GPO) 保护。
卡巴斯基安全解决方案能够有效检测攻击各个阶段所描述的恶意活动。以下列出了可能的检测场景。为了保护使用卡巴斯基 SIEM 系统的组织,我们准备了一套关联规则包,旨在帮助检测此类恶意活动。客户现在可以从 SIEM 存储库下载这些规则;规则包名称为:[OOTB] 组策略劫持:PAYLOAD 勒索软件 – ENG。
“组策略劫持:PAYLOAD 勒索软件”软件包包含一些规则,用于检测域控制器上 SYSVOL 共享文件夹中可疑文件的创建或修改,以及域组策略关键属性和设置的更改。如果某些规则因合法活动(例如域控制器之间的同步或新组策略的配置)而触发,则可能需要进行调整。
为确保检测规则正常运行,请验证是否已完整接收来自 Windows 系统的事件,包括具有以下标识符的事件:Sysmon: 11, Security — 4663, 5136, 4657。
我们还建议应用存储库中提供的以下规则来检测所有攻击阶段。
检测到清除 Windows 事件日志以掩盖攻击痕迹:R050_03_Windows 事件日志已被清除
检测到对 LSASS 进程的可疑访问,这可能表明有人试图转储凭据:R262_对 LSASS 进程的可疑访问
检测到卷影复制服务已启动,该服务用于在删除卷影副本之前创建它们:R231_20_正在运行卷影复制服务
检测到卷影副本删除:R321_卷影副本删除
检测到 Windows Defender 已禁用:R076_01_Windows Defender 防病毒软件已禁用
检测到尝试禁用或修改系统防火墙的行为:R240_03_通过注册表禁用系统防火墙
检测到从非系统文件夹安装的服务,这可能表明恶意软件采用了持久化技术:R281_01_从非系统文件夹安装服务
要使此列表中的规则正常工作,必须为事件 ID 4663、5136、4657、7036 和 1102 配置安全事件审核。
除了 SIEM 系统之外,当审计设置配置正确时,创建、修改和删除 GPO 的过程会在域控制器上生成大量特征工件,从而使 Kaspersky Endpoint Detection and Response Expert 能够及时提醒用户基础架构中的异常情况。
创建新的 GPO 由 gpo_creation 规则控制,该规则会在基础架构中发生相应事件时触发。对现有策略的更改由以下规则检测:
setting_the_gpcmachineextensionname_attribute 规则检测 gPCMachineExtensionNames 属性的更改。
setting_the_gpcfilesyspath_attribute 规则检测组策略对象的 gPCFileSysPath 属性的使用情况,该属性指定 SYSVOL 中 GPO 内容的路径。
更广泛的规则 setting_the_grouppolicycontainer_class 检测 groupPolicyContainer 类的更改。
GPO 删除操作由 gpo_deletion 规则控制。
在卡巴斯基 EDR Expert 的下一个主要版本更新中,将引入一种新的事件类型 GPO,允许用户跟踪组策略对象的更改。
对于信息安全官而言,GPO 事件将作为调查 Active Directory 中活动时的额外上下文来源,并有助于在部署潜在的恶意策略之前检测可能影响端点配置、访问权限和安全性的更改。
GPO 有效载荷勒索软件 GPO:{C897F2C7-C2AC-4E6F-BF48-58036FF29E79} win 防火墙关闭 GPO:{22099AD2-E062-4F56-B574-5099BBA4E7A6}
文件名和 MD5 哈希值 payload.jpg:勒索软件壁纸和锁屏图像 (SYSVOL) hello.txt:勒索信源代码 (SYSVOL) README-payload.txt:投放到桌面和驱动器根目录的勒索信 killer.exe ( 0108656A3E1ADE6CA4F21B084F5E1208 ):进程终止工具 kill.exe ( BEA5E267F24D7DA59F6821BFFDBFF293 ):进程终止工具
IP地址:37.19.210[.]12 146.70.117[.]239 149.102.229[.]154 104.164.55[.]46 104.28.162[.]228 104.28.163[.]162 64.190.76[.]14 192.42.116[.]50 192.42.116[.]12 192.42.116[.]56 192.42.116[.]97 192.42.116[.]52
注册表项 HKLM\...\Policies\System\legalnoticecaption = 欢迎使用 Payload!
SYSVOL 路径 \\DC.THECOMPANY.local\sysvol\THECOMPANY.local\payload.jpg
事件 ID 5137:在域控制器上创建 GPO 对象 — 查看创建者帐户;5136:GPO 属性修改 — 监视域根目录下的 gPLink
组策略被劫持:PAYLOAD 勒索软件利用 Active Directory GPO 攻击组策略对象
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