""ET TROJAN Ursnif Variant CnC Beacon 4""

SID: 2021829

Revision: 1

Class Type: trojan-activity

Metadata: attack_target Client_Endpoint, created_at 2015_09_24, deployment Perimeter, signature_severity Major, tag c2, updated_at 2015_09_24, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel

Reference:

  • md5

  • f870c0d62691fc39194922e4a59fdc1c

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: "."

  • Value: !"Accept"

  • Value: !"Referer|3a|"

  • Value: "User-Agent|3a 20|Mozilla/4.0 (compatible|3b| MSIE 8.0|3b| Windows NT 6.1)|0d 0a|Host|3a 20|" Depth: 70

  • Value: "Connection|3a 20|Keep-Alive|0d 0a|"

Within:

PCRE: "/\r\nHost\x3a[^\r\n]+\r\n(?:Content-Length\x3a\x20\d+\r\n)?Connection\x3a\x20Keep-Alive\r\n(?:Cache-Control|Pragma)\x3a\x20no-cache\r\n(?:\r\n)?$/H"

Special Options:

  • http_method

  • http_uri

  • http_header

  • http_header

  • http_header

  • http_header

source