""ET TROJAN Win32/MereTam.A Ransomware CnC Init Activity""

SID: 2032419

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_04_05, deployment Perimeter, signature_severity Major, tag Ransomware, updated_at 2021_04_05, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact

Reference:

  • md5

  • b306115dc9c137b0fa455a9ce1708917

Protocol: tcp

Source Network: $HOME_NET

Source Port: any

Destination Network: $EXTERNAL_NET

Destination Port: $HTTP_PORTS

Flow: established,to_server

Contents:

  • Value: "GET"

  • Value: "/?gen&session-id="

  • Value: !"Accept"

  • Value: !"Cache-|3a 20|"

  • Value: !"Referer|3a 20|"

  • Value: !"User-Agent|3a 20|"

Within:

PCRE: "/\/\?gen&session-id=[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$/Us"

Special Options:

  • http_method

  • fast_pattern

  • http_uri

  • http_header

  • http_header

  • http_header

  • http_header

source