""ET TROJAN Observed Malicious SSL Cert (Gelsemium CnC)""

SID: 2033152

Revision: 2

Class Type: trojan-activity

Metadata: affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2021_06_21, deployment Perimeter, performance_impact Low, signature_severity Major, tag SSL_Malicious_Cert, updated_at 2021_06_21, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol

Reference:

Protocol: tcp

Source Network: $EXTERNAL_NET

Source Port: 443

Destination Network: $HOME_NET

Destination Port: any

Flow: established,to_client

Contents:

  • Value: "|16|"

  • Value: "|0b|"

  • Value: "|06 03 55 04 06|"

  • Value: "|02|US"

  • Value: "|06 03 55 04 08|"

  • Value: "|02|IH"

  • Value: "|06 03 55 04 07|"

  • Value: "|02|IH"

  • Value: "|06 03 55 04 0a|"

  • Value: "|02|IH"

  • Value: "|06 03 55 04 0b|"

  • Value: "|02|IH"

  • Value: "|06 03 55 04 03|"

  • Value: "|02|IH"

  • Value: "|06 03 55 04 06|"

  • Value: "|02|US"

  • Value: "|06 03 55 04 08|"

  • Value: "|02|CA"

  • Value: "|06 03 55 04 07|"

  • Value: "|02|CA"

  • Value: "|06 03 55 04 0a|"

  • Value: "|02|CA"

  • Value: "|06 03 55 04 0b|"

  • Value: "|02|CA"

  • Value: "|06 03 55 04 03|"

  • Value: "|02|CA"

Within: 3

PCRE:

Special Options:

  • fast_pattern

source