/*
   Yara Rule Set
   Author: Florian Roth
   Date: 2018-06-23
   Identifier: Tick Group - Weaponized USB
   Reference: https://researchcenter.paloaltonetworks.com/2018/06/unit42-tick-group-weaponized-secure-usb-drives-target-air-gapped-critical-systems/
*/

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

import "pe"

rule APT_Tick_Sysmon_Loader_Jun18 {
   meta:
      description = "Detects Sysmon Loader from Tick group incident - Weaponized USB"
      license = "Detection Rule License 1.1 https://github.com/Neo23x0/signature-base/blob/master/LICENSE"
      author = "Florian Roth (Nextron Systems)"
      reference = "https://researchcenter.paloaltonetworks.com/2018/06/unit42-tick-group-weaponized-secure-usb-drives-target-air-gapped-critical-systems/"
      date = "2018-06-23"
      hash1 = "31aea8630d5d2fcbb37a8e72fe4e096d0f2d8f05e03234645c69d7e8b59bb0e8"
      id = "eae013c3-4774-5342-bd1a-5f2825612747"
   strings:
      $x1 = "SysMonitor_3A2DCB47" fullword ascii

      $s1 = "msxml.exe" fullword ascii
      $s2 = "wins.log" fullword ascii
      $s3 = "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\run" fullword ascii
      $s4 = "%2d-%2d-%2d-%2d" fullword ascii
      $s5 = "%USERPROFILE%" fullword ascii /* Goodware String - occured 22 times */
      $s6 = "Windows NT" fullword ascii /* Goodware String - occured 72 times */
      $s7 = "device monitor" fullword ascii
      $s8 = "\\Accessories" ascii
   condition:
      uint16(0) == 0x5a4d and filesize < 200KB and (
         pe.imphash() == "c5bb16e79fb500c430edce9481ae5b2b" or
         $x1 or 6 of them
      )
}

rule APT_Tick_HomamDownloader_Jun18 {
   meta:
      description = "Detects HomamDownloader from Tick group incident - Weaponized USB"
      license = "Detection Rule License 1.1 https://github.com/Neo23x0/signature-base/blob/master/LICENSE"
      author = "Florian Roth (Nextron Systems)"
      reference = "https://researchcenter.paloaltonetworks.com/2018/06/unit42-tick-group-weaponized-secure-usb-drives-target-air-gapped-critical-systems/"
      date = "2018-06-23"
      hash1 = "f817c9826089b49d251b8a09a0e9bf9b4b468c6e2586af60e50afe48602f0bec"
      id = "8ec52cb7-41a4-50a9-9cb1-23bee354680f"
   strings:
      $s1 = "cmd /c hostname >>" fullword ascii
      $s2 = "Mstray.exe" fullword ascii
      $s3 = "msupdata.exe" fullword ascii
      $s5 = "Windows\\CurrentVersion\\run" fullword ascii
      $s6 = "Content-Type: */*" fullword ascii
      $s11 = "Mozilla/4.0 (compatible; MSIE 8.0; Win32)" fullword ascii /* Goodware String - occured 3 times */
   condition:
      uint16(0) == 0x5a4d and filesize < 30KB and 3 of them
}