""ET TROJAN Cobalt Strike Malleable C2 OCSP Profile""

SID: 2032750

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 2017_05_15, deployment Perimeter, malware_family Cobalt_Strike, signature_severity Major, updated_at 2017_05_15, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation

Reference:

Protocol: tcp

Source Network: $HOME_NET

Source Port: any

Destination Network: $EXTERNAL_NET

Destination Port: $HTTP_PORTS

Flow: to_server,established

Contents:

  • Value: "GET"

  • Value: "/oscp/" Depth: 6

  • Value: "Host|3a 20|ocsp.verisign.com|0d 0a|Accept" Depth: 31

  • Value: "Microsoft-CryptoAPI/6.1"

  • Value: !"Referer|3a|"

Within:

PCRE: "/^\/oscp\/[a-z]+$/U"

Special Options:

  • http_method

  • http_uri

  • fast_pattern

  • http_header

  • http_header

  • http_header

source