""ET TROJAN Possible APT28 Xtunnel Activity""

SID: 2027405

Revision: 2

Class Type: trojan-activity

Metadata: affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, created_at 2019_05_30, deployment Perimeter, malware_family XTunnel, performance_impact Low, signature_severity Major, tag APT, updated_at 2019_05_31

Reference:

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: "User-Agent|3a 20|Mozilla|2f|4.0|20 28|compatible|3b 20|MSIE|20|7.0"

• Value: "deflate,sdch|0d 0a|Accept|3a 20|text|2f|html,application|2f|xhtml"

• Value: "Connection|3a 20|Close|0d|"

• Value: !"Referer|3a|"

• Value: !"Cache"

Within:

PCRE: "/^\/(?:\w+\/){1,5}\?[a-z]{1,6}=[a-z0-9]{2,40}(?:&[a-z]{1,6}=(?:[a-z0-9]){1,40}(%3D){0,2}){1,4}$/Ii"

Special Options:

• http_method

• http_header

• http_header

• http_header

• http_header

• http_header

source