""ET TROJAN Observed Karen Ransomware CnC Checkin""

SID: 2033772

Revision: 2

Class Type: trojan-activity

Metadata: affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_08_23, deployment Perimeter, signature_severity Major, tag Ransomware, updated_at 2023_04_05, reviewed_at 2024_06_26, 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:

Contents:

  • Value: "POST"

  • Value: "|2f|key|2f|"

  • Value: "Go|2d|http|2d|client"

  • Value: "Host|3a 20|karen|2e|"

  • Value: "id|3d|" Depth: 3

  • Value: "|2d|"

  • Value: "|2d|"

  • Value: "|2d|"

  • Value: "|2d|"

  • Value: "|26|key|3d|"

  • Value: !"Referer|3a 20|"

Within: 5

PCRE: "/id\x3d[a-z0-9]{8}\x2d[a-z0-9]{4}\x2d[a-z0-9]{4}\x2d[a-z0-9]{4}\x2d[a-z0-9]{12}\x26key\x3d[a-z0-9]{512}/P"

Special Options:

  • http_method

  • http_uri

  • http_header

  • http_header

  • fast_pattern

  • http_client_body

  • http_client_body

  • http_client_body

  • http_client_body

  • http_client_body

  • http_client_body

  • http_header

source