""ET TROJAN Observed Karen Ransomware Powershell Loader""

SID: 2033773

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_08_23, deployment Perimeter, signature_severity Major, tag Ransomware, updated_at 2021_08_23, 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: "GET"

  • Value: "|2f|loader|2f|loader2.ps1"

  • Value: "Go|2d|http|2d|client"

  • Value: "Host|3a 20|karen|2e|"

  • Value: !"Referer|3a 20|"

Within:

PCRE: "/^User-Agent\x3a\x20[^\r\n]+Go\x2dhttp\x2dclient/Hmi"

Special Options:

  • http_method

  • fast_pattern

  • http_uri

  • http_header

  • http_header

  • http_header

source