Suspicious File Download via certutil urlcache
- Product
- windows
- Category
- process_creation
- Author
- HuntRule
- Published
- 2026-09-28
- Updated
- 2026-09-28
ATT&CK techniques
Defense Evasion → C2Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
Exfiltration
Impact
What it detects
This rule detects certutil downloading a remote file with the urlcache flag, used after WS_FTP exploitation to pull a payload into the Windows Temp directory. Certutil is a certificate utility and its use to fetch content over HTTP is a well known living-off-the-land ingress and proxy download technique.
Reporting behind it
- huntress.comhttps://www.huntress.com/blog/critical-vulnerabilities-ws-ftp-exploitation
- attack.mitre.orghttps://attack.mitre.org/techniques/T1105/
- attack.mitre.orghttps://attack.mitre.org/techniques/T1218/
- unit42.paloaltonetworks.comhttps://unit42.paloaltonetworks.com/espionage-campaign-targets-south-asian-entities/
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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