xalgord Hunting For Shadow Copy Deletion
When to Use
- When proactively hunting for indicators of hunting for shadow copy deletion in the environment
- After threat intelligence indicates active campaigns using these techniques
- During incident response to scope compromise related to these techniques
- When EDR or SIEM alerts trigger on related indicators
- During periodic security assessments and purple team exercises
Detection Gaps & Validation
- Cover every deletion vector:
vssadmin delete shadows /all /quietis the loud case, but also huntwmic shadowcopy delete, PowerShellGet-WmiObject/Get-CimInstance Win32_ShadowCopy | Remove-*,bcdedit /set {default} recoveryenabled no,wbadmin delete catalog, and direct VSS COM API calls that spawn NO child process. - Match on args, not image name: renaming vssadmin.exe → svc.exe defeats Image-based rules — key on EID 1/4688 CommandLine (
delete shadows,resize shadowstorage) andOriginalFileName. - No-process deletions:
Win32_ShadowCopy.Delete()via a loaded DLL or WMI leaves no 4688/EID 1 — need WMI-Activity EID 5857/5861. - Validate: run Atomic T1490 vssadmin and wmic variants; confirm EID 1/4688 command lines are captured end to end.
- FP tuning: legit backup suites (Veeam, Acronis, Windows Backup) resize/delete shadows — baseline by signed parent process and expected schedule.
Prerequisites
- EDR platform with process and network telemetry (CrowdStrike, MDE, SentinelOne)
- SIEM with relevant log data ingested (Splunk, Elastic, Sentinel)
- Sysmon deployed with comprehensive configuration
- Windows Security Event Log forwarding enabled
- Threat intelligence feeds for IOC correlation
Workflow
- Formulate Hypothesis: Define a testable hypothesis based on threat intelligence or ATT&CK gap analysis.
- Identify Data Sources: Determine which logs and telemetry are needed to validate or refute the hypothesis.
- Execute Queries: Run detection queries against SIEM and EDR platforms to collect relevant events.
- Analyze Results: Examine query results for anomalies, correlating across multiple data sources.
- Validate Findings: Distinguish true positives from false positives through contextual analysis.
- Correlate Activity: Link findings to broader attack chains and threat actor TTPs.
- Document and Report: Record findings, update detection rules, and recommend response actions.
Key Concepts
| Concept | Description |
|---|---|
| T1490 | Inhibit System Recovery |
| T1486 | Data Encrypted for Impact |
| T1485 | Data Destruction |
Tools & Systems
| Tool | Purpose |
|---|---|
| CrowdStrike Falcon | EDR telemetry and threat detection |
| Microsoft Defender for Endpoint | Advanced hunting with KQL |
| Splunk Enterprise | SIEM log analysis with SPL queries |
| Elastic Security | Detection rules and investigation timeline |
| Sysmon | Detailed Windows event monitoring |
| Velociraptor | Endpoint artifact collection and hunting |
| Sigma Rules | Cross-platform detection rule format |
Common Scenarios
- Scenario 1: Ransomware deleting shadow copies before encryption
- Scenario 2: vssadmin delete shadows /all /quiet pre-encryption
- Scenario 3: WMIC shadowcopy delete via PowerShell
- Scenario 4: bcdedit disabling recovery mode before impact
Output Format
Hunt ID: TH-HUNTIN-[DATE]-[SEQ]
Technique: T1490
Host: [Hostname]
User: [Account context]
Evidence: [Log entries, process trees, network data]
Risk Level: [Critical/High/Medium/Low]
Confidence: [High/Medium/Low]
Recommended Action: [Containment, investigation, monitoring]