""ET TROJAN Mespinoza Ransomware - Pre-Encryption File Exfil to CnC""

SID: 2033343

Revision: 1

Class Type: trojan-activity

Metadata: affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_07_15, deployment Perimeter, malware_family Mespinoza, signature_severity Major, tag Ransomware, updated_at 2021_07_15, 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: $HTTP_PORTS

Flow: established,to_server

Contents:

  • Value: "/upload-" Depth: 8

  • Value: "?token="

  • Value: "&id="

  • Value: "&fullPath="

Within:

PCRE: "/\?token=(?:[A-Z0-9+/]{4})*(?:[A-Z0-9+/]{2}==|[A-Z0-9+/]{3}=|[A-Z0-9+/]{4})/U"

Special Options:

  • fast_pattern

  • http_uri

  • http_uri

  • http_uri

  • http_uri

source