""ET TROJAN Win32/Atomsilo Ransomware Activity (POST)""

SID: 2038577

Revision: 1

Class Type: trojan-activity

Metadata: attack_target Client_Endpoint, created_at 2022_08_22, deployment Perimeter, malware_family LockBit, malware_family AtomSilo, signature_severity Major, tag Ransomware, updated_at 2022_08_22, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact

Reference:

Protocol: tcp

Source Network: $HOME_NET

Source Port: any

Destination Network: $EXTERNAL_NET

Destination Port: any

Flow: established,to_server

Contents:

  • Value: "POST"

  • Value: ".php|20|"

  • Value: "User-Agent|3a 20|Microsoft|0d 0a|"

  • Value: "blocknum="

  • Value: "&computername="

  • Value: "&base64privkey="

  • Value: "&base64pubkey="

Within:

PCRE:

Special Options:

  • fast_pattern

source