""ET TROJAN Observed Cobalt Strike CnC Domain (defenderupdateav .com in TLS SNI)""

SID: 2033799

Revision: 1

Class Type: trojan-activity

Metadata: attack_target Client_Endpoint, created_at 2021_08_25, deployment Perimeter, malware_family Cobalt_Strike, signature_severity Major, updated_at 2021_08_25, 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: 443

Flow: established,to_server

Contents:

  • Value: "|16|" Depth: 1

  • Value: "|01|"

  • Value: "|00 00 14|defenderupdateav.com"

Within:

PCRE:

Special Options:

source