Malicious Cron Payload Retrieval via curl to Attacker Shell Scripts

ATT&CK techniques

Execution

Recon
Resource Dev
Initial Access
Execution
- T1059.004Unix Shell
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects curl fetching the attacker cron installer scripts cronb.sh or cronis.sh used in the exposed Docker campaign. After escaping the container the attackers pull these shell scripts to establish cron persistence and drop cryptominers and a rootkit. Retrieval of these named payload scripts is a high-signal indicator of this coinmining intrusion.

Reporting behind it

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Malicious EtherRAT Base64 Decoded Payload Piped To Bash via Shell (via process_creation)

Suspicious Bash Decode Chain Using curl xxd and base64 Piped to eval via Linux Shell

Malicious Download Piped to Shell via curl or wget (via process_creation)

Malicious Cron Payload Retrieval via curl to Attacker Shell Scripts

Pivot detection · T1059.004 · 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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