In-Memory VShell Downloader Piping curl and wget Fallback Into Shell (via process_creation)

ATT&CK techniques

C2

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1105Ingress Tool Transfer
Exfiltration
Impact

What it detects

This rule detects a single command line that combines curl and a wget fallback and pipes the retrieved payload directly into a shell, the download-and-execute pattern used by VShell to fetch its second stage from the C2 server. Adversaries leverage the dual-tool fallback to survive missing utilities and run code without touching disk, making detection of this construct useful for catching in-memory staging on Linux.

Reporting behind it

Related detections9 linkedT1105 — drag to rearrange

Suspicious Hidden PowerShell WebClient DownloadFile Cradle

Suspicious PowerShell Download Cradle with Spoofed User-Agent via MSIX

Malicious PowerShell In-Memory Download Cradle via Script Block (via ps_script)

Suspicious Remote Access Tool User Agent in Outbound Traffic via Proxy

Malicious Hidden Virtual Machine Launched via QEMU for Persistence

Suspicious node.exe Execution Spawned by PowerShell

Suspicious Executable Download to Temp Directory via curl on Linux

Suspicious BITSAdmin File Transfer Into ProgramData via Process Creation (via process_creation)

Suspicious PowerShell Download Cradle via IEX and DownloadString (via process_creation)

In-Memory VShell Downloader Piping curl and wget Fallback Into Shell (via process_creation)

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.

Full detection rule

Unlock this rule to view and copy it

The detection logic is included with a plan. Everything else — context, mappings and implementation details — stays free on this page.

Sign in for 3 free unlocks

Signing in gives you 3 unlocks to spend on any rule in the library. No card, and they do not expire.

Also included

Unlocked rules convert on this page — to Splunk SPL or Splunk — Raw Index SPL or Microsoft Sentinel KQL or Microsoft Sentinel ASIM ASIM KQL or Microsoft Defender XDR KQL or Elastic Security KQL or Elastic Security Lucene or Elastic Security ES|QL or CrowdStrike Falcon CQL or SentinelOne PowerQuery or Palo Alto Cortex XDR XQL or Carbon Black Cloud Platform Search or Carbon Black EDR Process Search or Google Security Operations UDM Search or IBM QRadar AQL or Sumo Logic Cloud SIEM Rules expression or Rapid7 InsightIDR LEQL or Graylog Search or OpenSearch Lucene or OpenSearch PPL PPL or Grafana Loki LogQL or SQLite SQL or Zircolite SQLite — with the log-source profile the engine picked, the field map it used, and everything it could not express. Converting a rule you have unlocked costs no further credit.

See it run on a free rule →Convert your own rule →