Malicious C2 Download Embedding Host Reconnaissance in URL

PremiumReviewedSigma · High · v1
Product
linux
Category
process_creation
Author
HuntRule
Published
2026-08-16
Updated
2026-08-28

ATT&CK techniques

C2
  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. Exfiltration

  13. Impact

What it detects

This rule detects wget or curl fetching a URL that embeds command substitution such as the current username, a beaconing pattern where the backdoor reports host context to its C2 while retrieving the next stage. Encoding whoami output into the request lets the operator track and profile infected hosts.

Related detections9 linkedT1105 — drag to rearrange
Malicious Curl Download From C2 CAPTCHA Path via Process Creation
Suspicious File Upload via curl Multipart Form
Possible GCleaner Loader C2 Check-in via cpa ping php Endpoint via proxy
TAG-144 Payload Staging via MyCustomAgent User-Agent (via proxy)
Possible NetHealth Implant C2 Beacon URI Pattern
LightSpy macOS Implant PID File Creation in Users Shared
Possible Remcos C2 Connection from eilowutil Process
Suspicious Remote HTA Payload Execution via MSHTA
Possible PurpleFox MSHTA to Msiexec Remote MSI Chain
Malicious C2 Download Embedding Host Reconnaissance in URL
Pivot detection · T1105 · 9 related

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