signature-base/yara/apt_cmstar.yar

/*
   Yara Rule Set
   Author: Florian Roth
   Date: 2017-10-03
   Identifier: CMStar Threat Actor
   Reference: https://goo.gl/pTffPA
*/

/* Rule Set ----------------------------------------------------------------- */

import "pe"

rule CMStar_Malware_Sep17 {
   meta:
      description = "Detects CMStar Malware"
      author = "Florian Roth"
      reference = "https://goo.gl/pTffPA"
      date = "2017-10-03"
      hash1 = "16697c95db5add6c1c23b2591b9d8eec5ed96074d057b9411f0b57a54af298d5"
   strings:
      $s1 = "UpdateService.tmp" fullword ascii
      $s2 = "StateNum:%d,FileSize:%d" fullword ascii
   condition:
      uint16(0) == 0x5a4d and filesize < 100KB and (
         pe.imphash() == "22021985de78a48ea8fb82a2ff9eb693" or
         pe.exports("WinCred") or
         all of them
      )
}