Detection rules › Splunk

Windows Archive Collected Data via Powershell

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic detects the use of PowerShell scripts to archive files into a temporary folder. It leverages PowerShell Script Block Logging, specifically monitoring for the Compress-Archive command targeting the Temp directory. This activity is significant as it may indicate an adversary's attempt to collect and compress data for exfiltration. If confirmed malicious, this behavior could lead to unauthorized data access and exfiltration, posing a severe risk to sensitive information and overall network security.

MITRE ATT&CK coverage

TacticTechniques
CollectionT1560 Archive Collected Data

Event coverage

ProviderEvent IDTitle
PowerShell4104Creating Scriptblock text (MessageNumber of MessageTotal).

Stages and Predicates

Stage 1: search

search EventCode=4104 ScriptBlockText="*Compress-Archive*" ScriptBlockText="*\\Temp\\*"

Stage 2: fillnull

fillnull

Stage 3: stats

stats BY dest, signature, signature_id, user_id, vendor_product, EventID, Guid, Opcode, Name, Path, ProcessID, ScriptBlockId, ScriptBlockText

Stage 4: search

search

Stage 5: search

search

Stage 6: search

search `macro`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
EventCodeeq
  • 4104 corpus 108 (splunk 108)
ScriptBlockTexteq
  • "*Compress-Archive*"
  • "*\\Temp\\*"

Neighbors

Broader alternatives (more inclusive than this rule)

These rules match a superset of what this rule catches. They cover the same events plus more. Use them if you want wider coverage and can absorb more false positives.