--- name: detecting-evasion-techniques-in-endpoint-logs-c2bf7021da96 description: 'Detects defense evasion techniques used by adversaries in endpoint logs including log tampering, timestomping, process injection, and security tool disabling. Use when investigating suspicious endpoint behavior, building detection rules for evasion tactics, or conducting threat hunting for stealthy adversary activity. Activates for requests involving evasion detection, defense evasion analysis, log tampering detection, or MITRE ATT&CK TA0005. ' domain: cybersecurity subdomain: endpoint-security tags: - endpoint - edr - threat-hunting - defense-evasion - MITRE-ATT&CK - detection-engineering version: 1.0.0 author: mahipal license: Apache-2.0 d3fend_techniques: - File Metadata Consistency Validation - Content Format Conversion - File Content Analysis - Platform Hardening - File Format Verification nist_csf: - PR.PS-01 - PR.PS-02 - DE.CM-01 - PR.IR-01 mitre_attack: - T1055 - T1547 - T1059 - T1036 - T1027 --- # Detecting Evasion Techniques in Endpoint Logs ## When to Use Use this skill when: - Hunting for adversary defense evasion techniques (MITRE ATT&CK TA0005) in endpoint telemetry - Building detection rules for common evasion methods (process injection, timestomping, log clearing) - Investigating incidents where adversaries disabled or bypassed security tools - Analyzing endpoint logs for indicators of living-off-the-land binary (LOLBin) abuse **Do not use** this skill for network-level evasion (use network traffic analysis) or for malware reverse engineering. ## Prerequisites - Sysmon installed and configured with comprehensive logging rules (SwiftOnSecurity or Olaf Hartong config) - Windows Security Event Log with advanced audit policy enabled - EDR telemetry (CrowdStrike, SentinelOne, Microsoft Defender for Endpoint) - SIEM platform for log correlation (Splunk, Elastic, Sentinel) - MITRE ATT&CK Enterprise matrix for technique reference ## Workflow ### Step 1: Detect Log Tampering (T1070) **Windows Event Log clearing (T1070.001)**: ``` # Sysmon Event ID 1 (Process Create) for wevtutil EventID: 1 CommandLine contains: "wevtutil cl" OR "wevtutil clear-log" # Security Event ID 1102 - Audit log was cleared EventID: 1102 Source: Microsoft-Windows-Eventlog # System Event ID 104 - Event log was cleared EventID: 104 # PowerShell log clearing EventID: 1 (Sysmon) CommandLine contains: "Clear-EventLog" OR "Remove-EventLog" # Splunk query: index=windows (EventCode=1102 OR EventCode=104) OR (EventCode=1 CommandLine="*wevtutil*cl*") OR (EventCode=1 CommandLine="*Clear-EventLog*") | table _time host user CommandLine EventCode ``` **Timestomping (T1070.006)**: ``` # Sysmon Event ID 2 - File creation time changed EventID: 2 # Look for creation times set far in the past on recently-written files # Correlate with Event ID 11 (FileCreate) - if FileCreate is recent but # creation time in Event ID 2 is old, timestomping is likely # MDE Advanced Hunting (KQL): DeviceFileEvents | where ActionType == "FileTimestampModified" | where Timestamp > ago(7d) | extend TimeDiff = datetime_diff('day', Timestamp, ReportedFileCreationTime) | where TimeDiff > 30 | project Timestamp, DeviceName, FileName, FolderPath, ReportedFileCreationTime, InitiatingProcessFileName ``` ### Step 2: Detect Process Injection (T1055) ``` # Sysmon Event ID 8 - CreateRemoteThread EventID: 8 # Alert when source process is unusual (not system processes) # Filter out known legitimate: antivirus, debugging tools SourceImage NOT IN ("C:\Windows\System32\csrss.exe", "C:\Windows\System32\lsass.exe") # Sysmon Event ID 10 - ProcessAccess with suspicious access masks EventID: 10 GrantedAccess contains: "0x1F0FFF" OR "0x1FFFFF" OR "0x001F0FFF" # PROCESS_ALL_ACCESS = 0x1F0FFF (common in injection) # Filter legitimate: AV accessing all processes # Sysmon Event ID 25 - Process Tampering EventID: 25 Type: "Image is replaced" # Process hollowing indicator # Splunk detection: index=sysmon EventCode=8 | where NOT match(SourceImage, "(?i)(csrss|svchost|MsMpEng|defender)") | stats count by SourceImage TargetImage host | where count < 5 | sort - count ``` ### Step 3: Detect Security Tool Disabling (T1562) ``` # Service stopped events for security services EventID: 7045 (new service) OR 7036 (service state change) ServiceName IN ("WinDefend", "Sense", "CrowdStrike Falcon Sensor", "SentinelAgent", "csagent", "MBAMService") # Sysmon Event ID 1 - Processes that disable Defender CommandLine contains: "Set-MpPreference -DisableRealtimeMonitoring" OR "sc stop WinDefend" OR "sc config WinDefend start= disabled" OR "net stop" AND ("windefend" OR "sense" OR "csagent") # Registry modification to disable security features # Sysmon Event ID 13 - Registry value set TargetObject contains: "DisableAntiSpyware" OR "DisableRealtimeMonitoring" OR "DisableBehaviorMonitoring" Details: "DWORD (0x00000001)" # MDE KQL: DeviceRegistryEvents | where RegistryValueName in ("DisableAntiSpyware", "DisableRealtimeMonitoring") | where RegistryValueData == "1" | project Timestamp, DeviceName, RegistryKey, InitiatingProcessFileName ``` ### Step 4: Detect Masquerading (T1036) ``` # Sysmon Event ID 1 - Process with legitimate name from unusual path EventID: 1 Image contains: "svchost.exe" AND Image NOT starts with: "C:\Windows\System32\" Image contains: "csrss.exe" AND Image NOT starts with: "C:\Windows\System32\" Image contains: "lsass.exe" AND Image NOT starts with: "C:\Windows\System32\" # Process name mismatch (original filename vs. current name) # Sysmon captures OriginalFileName from PE header EventID: 1 OriginalFileName != (parsed filename from Image path) # Double extension files EventID: 11 (FileCreate) TargetFilename matches: "*\.pdf\.exe" OR "*\.doc\.exe" OR "*\.jpg\.exe" # Splunk: index=sysmon EventCode=1 | eval process_name=mvindex(split(Image,"\\"),-1) | where (process_name="svchost.exe" AND NOT match(Image,"(?i)C:\\\\Windows\\\\System32")) OR (process_name="csrss.exe" AND NOT match(Image,"(?i)C:\\\\Windows\\\\System32")) | table _time host Image ParentImage CommandLine User ``` ### Step 5: Detect LOLBin Abuse (T1218, T1127) ``` # Common LOLBin abuse patterns: # mshta.exe executing remote content EventID: 1 Image ends with: "mshta.exe" CommandLine contains: "http" OR "javascript:" OR "vbscript:" # certutil.exe downloading files EventID: 1 Image ends with: "certutil.exe" CommandLine contains: "-urlcache" OR "-decode" OR "-encode" # regsvr32.exe executing scriptlets EventID: 1 Image ends with: "regsvr32.exe" CommandLine contains: "/s /n /u /i:" OR "scrobj.dll" # rundll32.exe with unusual DLLs EventID: 1 Image ends with: "rundll32.exe" CommandLine contains: "javascript:" OR ".js" OR "http:" # MSBuild executing inline tasks EventID: 1 Image contains: "MSBuild.exe" CommandLine NOT contains: ".sln" AND NOT contains: ".csproj" ``` ### Step 6: Build Detection Rule Correlation ``` # Combine multiple weak signals into high-confidence detection: # Rule: Potential post-exploitation evasion chain # Trigger when 3+ evasion techniques observed on same host within 1 hour # Splunk correlation search: index=sysmon host=* | eval technique=case( EventCode=2, "timestomping", EventCode=8 AND NOT match(SourceImage,"csrss|svchost"), "process_injection", EventCode=1 AND match(CommandLine,"(?i)wevtutil.*cl"), "log_clearing", EventCode=13 AND match(TargetObject,"DisableRealtimeMonitoring"), "security_disable", EventCode=1 AND match(CommandLine,"(?i)(mshta|certutil.*urlcache|regsvr32.*/s.*/n)"), "lolbin_abuse", true(), NULL ) | where isnotnull(technique) | bin _time span=1h | stats dc(technique) as technique_count values(technique) as techniques by host _time | where technique_count >= 3 | sort - technique_count ``` ## Key Concepts | Term | Definition | |------|-----------| | **Defense Evasion (TA0005)** | MITRE ATT&CK tactic where adversaries attempt to avoid detection during operations | | **Process Injection (T1055)** | Technique of injecting code into another process's memory space to execute in a trusted context | | **Timestomping (T1070.006)** | Modifying file timestamps to make malicious files appear old and blend with legitimate files | | **Masquerading (T1036)** | Naming malicious files or processes to match legitimate system files to avoid detection | | **LOLBin** | Living Off the Land Binary; legitimate Windows tool repurposed by adversaries | | **Indicator Removal (T1070)** | Clearing logs, deleting files, or modifying artifacts to remove evidence of compromise | ## Tools & Systems - **Sysmon**: Advanced Windows system monitoring with kernel-level visibility - **Microsoft Defender for Endpoint**: EDR with advanced hunting (KQL) for evasion detection - **CrowdStrike Falcon**: IOA-based behavioral detection for evasion techniques - **Elastic Security**: SIEM with prebuilt detection rules for ATT&CK evasion techniques - **Sigma Rules**: Vendor-agnostic detection rule format with extensive evasion rule library ## Common Pitfalls - **Alert fatigue from process injection rules**: Many legitimate tools (AV, accessibility) perform process injection. Maintain an allowlist of known-good source processes. - **Missing Sysmon Event ID 8/10**: Default Sysmon configurations may not capture CreateRemoteThread or ProcessAccess. Use a comprehensive Sysmon config. - **Ignoring parent process context**: A suspicious command line from cmd.exe is concerning only if the parent of cmd.exe is unusual (e.g., Excel spawning cmd.exe). - **Not correlating across event types**: Single events are often benign. Combine multiple weak signals (process creation + network connection + file creation) for high-confidence detections. --- Source attribution: costrict-plugins-repo Original project: https://github.com/costrict-plugins-repo/mukul975-anthropic-cybersecurity-skills-cybersecurity-skills/blob/1b344d155f00bae5cf27d8eba9508e8f5050d904/skills/detecting-evasion-techniques-in-endpoint-logs/SKILL.md License: Apache-2.0 License information: https://www.apache.org/licenses/LICENSE-2.0 Original upstream instructions; downloaded from Dave AI. ## Upstream license notice Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. Definitions. "License" shall mean the terms and conditions for use, reproduction, and distribution as defined by Sections 1 through 9 of this document. "Licensor" shall mean the copyright owner or entity authorized by the copyright owner that is granting the License. "Legal Entity" shall mean the union of the acting entity and all other entities that control, are controlled by, or are under common control with that entity. For the purposes of this definition, "control" means (i) the power, direct or indirect, to cause the direction or management of such entity, whether by contract or otherwise, or (ii) ownership of fifty percent (50%) or more of the outstanding shares, or (iii) beneficial ownership of such entity. "You" (or "Your") shall mean an individual or Legal Entity exercising permissions granted by this License. "Source" form shall mean the preferred form for making modifications, including but not limited to software source code, documentation source, and configuration files. "Object" form shall mean any form resulting from mechanical transformation or translation of a Source form, including but not limited to compiled object code, generated documentation, and conversions to other media types. "Work" shall mean the work of authorship, whether in Source or Object form, made available under the License, as indicated by a copyright notice that is included in or attached to the work (an example is provided in the Appendix below). "Derivative Works" shall mean any work, whether in Source or Object form, that is based on (or derived from) the Work and for which the editorial revisions, annotations, elaborations, or other modifications represent, as a whole, an original work of authorship. For the purposes of this License, Derivative Works shall not include works that remain separable from, or merely link (or bind by name) to the interfaces of, the Work and Derivative Works thereof. "Contribution" shall mean any work of authorship, including the original version of the Work and any modifications or additions to that Work or Derivative Works thereof, that is intentionally submitted to the Licensor for inclusion in the Work by the copyright owner or by an individual or Legal Entity authorized to submit on behalf of the copyright owner. For the purposes of this definition, "submitted" means any form of electronic, verbal, or written communication sent to the Licensor or its representatives, including but not limited to communication on electronic mailing lists, source code control systems, and issue tracking systems that are managed by, or on behalf of, the Licensor for the purpose of discussing and improving the Work, but excluding communication that is conspicuously marked or otherwise designated in writing by the copyright owner as "Not a Contribution." "Contributor" shall mean Licensor and any individual or Legal Entity on behalf of whom a Contribution has been received by the Licensor and subsequently incorporated within the Work. 2. Grant of Copyright License. Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare Derivative Works of, publicly display, publicly perform, sublicense, and distribute the Work and such Derivative Works in Source or Object form. 3. Grant of Patent License. Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this section) patent license to make, have made, use, offer to sell, sell, import, and otherwise transfer the Work, where such license applies only to those patent claims licensable by such Contributor that are necessarily infringed by their Contribution(s) alone or by combination of their Contribution(s) with the Work to which such Contribution(s) was submitted. If You institute patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the Work or a Contribution incorporated within the Work constitutes direct or contributory patent infringement, then any patent licenses granted to You under this License for that Work shall terminate as of the date such litigation is filed. 4. Redistribution. You may reproduce and distribute copies of the Work or Derivative Works thereof in any medium, with or without modifications, and in Source or Object form, provided that You meet the following conditions: (a) You must give any other recipients of the Work or Derivative Works a copy of this License; and (b) You must cause any modified files to carry prominent notices stating that You changed the files; and (c) You must retain, in the Source form of any Derivative Works that You distribute, all copyright, patent, trademark, and attribution notices from the Source form of the Work, excluding those notices that do not pertain to any part of the Derivative Works; and (d) If the Work includes a "NOTICE" text file as part of its distribution, then any Derivative Works that You distribute must include a readable copy of the attribution notices contained within such NOTICE file, excluding any notices that do not pertain to any part of the Derivative Works, in at least one of the following places: within a NOTICE text file distributed as part of the Derivative Works; within the Source form or documentation, if provided along with the Derivative Works; or, within a display generated by the Derivative Works, if and wherever such third-party notices normally appear. The contents of the NOTICE file are for informational purposes only and do not modify the License. You may add Your own attribution notices within Derivative Works that You distribute, alongside or as an addendum to the NOTICE text from the Work, provided that such additional attribution notices cannot be construed as modifying the License. You may add Your own copyright statement to Your modifications and may provide additional or different license terms and conditions for use, reproduction, or distribution of Your modifications, or for any such Derivative Works as a whole, provided Your use, reproduction, and distribution of the Work otherwise complies with the conditions stated in this License. 5. Submission of Contributions. Unless You explicitly state otherwise, any Contribution intentionally submitted for inclusion in the Work by You to the Licensor shall be under the terms and conditions of this License, without any additional terms or conditions. Notwithstanding the above, nothing herein shall supersede or modify the terms of any separate license agreement you may have executed with Licensor regarding such Contributions. 6. Trademarks. This License does not grant permission to use the trade names, trademarks, service marks, or product names of the Licensor, except as required for reasonable and customary use in describing the origin of the Work and reproducing the content of the NOTICE file. 7. Disclaimer of Warranty. Unless required by applicable law or agreed to in writing, Licensor provides the Work (and each Contributor provides its Contributions) on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are solely responsible for determining the appropriateness of using or redistributing the Work and assume any risks associated with Your exercise of permissions under this License. 8. Limitation of Liability. In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall any Contributor be liable to You for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising as a result of this License or out of the use or inability to use the Work (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if such Contributor has been advised of the possibility of such damages. 9. Accepting Warranty or Additional Liability. While redistributing the Work or Derivative Works thereof, You may choose to offer, and charge a fee for, acceptance of support, warranty, indemnity, or other liability obligations and/or rights consistent with this License. However, in accepting such obligations, You may act only on Your own behalf and on Your sole responsibility, not on behalf of any other Contributor, and only if You agree to indemnify, defend, and hold each Contributor harmless for any liability incurred by, or claims asserted against, such Contributor by reason of your accepting any such warranty or additional liability. END OF TERMS AND CONDITIONS APPENDIX: How to apply the Apache License to your work. To apply the Apache License to your work, attach the following boilerplate notice, with the fields enclosed by brackets "[]" replaced with your own identifying information. (Don't include the brackets!) The text should be enclosed in the appropriate comment syntax for the file format. Please do not remove or change the license header comment from a contributed file except when necessary. Copyright 2026 mukul975 Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. # Dave AI resource metadata Creator / publisher: costrict-plugins-repo Original project: https://github.com/costrict-plugins-repo/mukul975-anthropic-cybersecurity-skills-cybersecurity-skills/blob/1b344d155f00bae5cf27d8eba9508e8f5050d904/skills/detecting-evasion-techniques-in-endpoint-logs/SKILL.md Attribution basis: Source repository record Fields of work: Data & Analytics, Development & Engineering, Operations Roles: Data Analyst, Operations Manager, Security Engineer Specialties: API, Testing Tools: Elastic, Sentinel, Splunk, Sysmon Country applicability: Country not specified Classification basis: Source catalog labels Instruction SHA-256: 8d1116815cce05fa5dbb8ebfa31188252e2e57882bed0858c27d44dab059f7a7