""ET TROJAN Possible Kelihos Infection Executable Download With Malformed Header""

SID: 2018241

Revision: 1

Class Type: trojan-activity

Metadata: created_at 2014_03_09, updated_at 2014_03_09

Reference:

Protocol: tcp

Source Network: $EXTERNAL_NET

Source Port: $HTTP_PORTS

Destination Network: $HOME_NET

Destination Port: any

Flow: established,from_server

Contents:

  • Value: "Last-Modified|3a|"

  • Value: "MZ"

  • Value: "PE|00 00|"

Within: 4

PCRE: "/^Last-Modified\x3a(?:\s[^\r\n]{2}|[^\r\n\s]{3}),/Dm"

Special Options:

  • http_header

  • file_data

  • fast_pattern

source