Suspicious DLL Written to Explorer IconCache Path

ATT&CK techniques

Initial Access → Execution

Recon
Resource Dev
Initial Access
- T1566.001Spearphishing Attachment
Execution
- T1204.002Malicious File
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects a DLL written to the Explorer icon cache directory using an iconcache prefixed name with a numeric suffix. In Operation ForumTroll a LNK triggered PowerShell chain dropped a payload DLL named iconcache_<4digits>.dll to this location as reported by Kaspersky. Legitimate icon cache files use the .db extension so a .dll in this path is a strong masquerading and payload staging indicator.

Reporting behind it

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Suspicious DLL Written to Explorer IconCache Path

Pivot detection · T1204.002 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

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