Webapp Hunting For Shadow Copy Deletion

---
name: webapp-hunting-for-shadow-copy-deletion
description: Hunt for Volume Shadow Copy deletion activity that indicates ransomware preparation or anti-forensics by monitoring vssadmin, wmic, and PowerShell shadow copy commands.
domain: webapp
category: threat-intelligence
hide: true
license: Apache-2.0
metadata:
  manifest_entry: src/corpus/webapp-hunting-for-shadow-copy-deletion/SKILL.md
---
# 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 /quiet` is the loud case, but also hunt `wmic shadowcopy delete`, PowerShell `Get-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`) and `OriginalFileName`.
- **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

1. **Formulate Hypothesis**: Define a testable hypothesis based on threat intelligence or ATT&CK gap analysis.
2. **Identify Data Sources**: Determine which logs and telemetry are needed to validate or refute the hypothesis.
3. **Execute Queries**: Run detection queries against SIEM and EDR platforms to collect relevant events.
4. **Analyze Results**: Examine query results for anomalies, correlating across multiple data sources.
5. **Validate Findings**: Distinguish true positives from false positives through contextual analysis.
6. **Correlate Activity**: Link findings to broader attack chains and threat actor TTPs.
7. **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

1. **Scenario 1**: Ransomware deleting shadow copies before encryption
2. **Scenario 2**: vssadmin delete shadows /all /quiet pre-encryption
3. **Scenario 3**: WMIC shadowcopy delete via PowerShell
4. **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]
```