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

SID: 2029602

Revision: 2

Class Type: trojan-activity

Metadata: attack_target Client_and_Server, created_at 2020_03_10, deployment Perimeter, malware_family ServHelper, performance_impact Low, signature_severity Major, tag SSL_Malicious_Cert, updated_at 2020_03_10, 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: from_server,established

Contents:

  • Value: "|16|"

  • Value: "|0b|"

  • Value: "|55 04 03|"

  • Value: "|0b|kuarela.xyz"

  • Value: "|55 04 06|"

  • Value: "|02|US"

  • Value: "|55 04 0a|"

  • Value: "|0d|Let's Encrypt"

  • Value: "|55 04 03|"

  • Value: "|1a|Let's Encrypt Authority X3"

Within: 27

PCRE:

Special Options:

  • fast_pattern

source