YARA Detection Rule: BronzeButler_Daserf_C_1
Repository: Neo23x0/signature-base
Detects: Detects malware / hacktool sample from Bronze Butler incident
Author: Florian Roth (Nextron Systems)
Reference: https://www.secureworks.com/research/bronze-butler-targets-japanese-businesses

Pattern signatures:
$s1 = "(c) 2010 DYAMAR EnGineerinG, All rights reserved, http://www.dyamar.com." fullword ascii
      $s2 = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; SV1)" fullword ascii

      $a1 = "ndkkwqgcm" fullword ascii
      $a2 = "RtlGetCo" fullword ascii
      $a3 = "hutils" fullword ascii

      $b1 = "%USERPROFILE%\\System" fullword ascii
      $b2 = "msid.dat" fullword ascii
      $b3 = "DRIVE_REMOTE" fullword wide
      $b4 = "%s%s%s%s%s%s%s%s%s%s%s%s" fullword ascii
      $b5 = "jcbhe.asp" fullword ascii
      $b6 = "edset.asp" fullword ascii
      $b7 = "bxcve.asp" fullword ascii
      $b8 = "hcvery.php" fullword ascii
      $b9 = "ynhkef.php" fullword ascii
      $b10 = "dkgwey.php" fullword ascii

Detection condition:
uint16(0) == 0x5a4d and filesize < 300KB and (
         pe.imphash() == "088382f4887e3b2c4bd5157f2d72b618" or
         all of ($a*) or
         4 of them
      )

Full rule:
rule BronzeButler_Daserf_C_1 {
   meta:
      description = "Detects malware / hacktool sample from Bronze Butler incident"
      license = "Detection Rule License 1.1 https://github.com/Neo23x0/signature-base/blob/master/LICENSE"
      author = "Florian Roth (Nextron Systems)"
      reference = "https://www.secureworks.com/research/bronze-butler-targets-japanese-businesses"
      date = "2017-10-14"
      hash1 = "a4afd9df1b4cc014c3a89d7b4a560fa3e368b02286c[PII_REDACTED]4b23e68cc05"
      hash2 = "90ac1fb148ded4f46949a5fea4cd8c65d4ea9585046d66459328a5866f8198b2"
      hash3 = "331ac0965b50958db49b7794cc819b2945d7b5e5e919c185d83e997e205f107b"
      hash4 = "b1fdc6dc330e78a66757b77cc67a0e9931b777cd7af9f839911eecb74c04420a"
      hash5 = "15abe7b1355cd35375de6dde57608f6d3481755fdc9e71d2bfc7c7288db4cd92"
      hash6 = "85544d2bcaf8e6ca32bbc0a9e9583c9db1dce837043f555a7ff66363d5858439"
      hash7 = "2dc24622c1e91642a21a64c0dd31cbe953e8f77bd3d6abcf2c4676c3b11bb162"
      hash8 = "2bdb88fa24cffba240b[PII_REDACTED]9c76a9920b6c3f6e09c3c4b171c2f57031c"
      id = "62a5cc4a-7c58-5e4d-ac23-8d1f850a540a"
   strings:
      $s1 = "(c) 2010 DYAMAR EnGineerinG, All rights reserved, http://www.dyamar.com." fullword ascii
      $s2 = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; SV1)" fullword ascii

      $a1 = "ndkkwqgcm" fullword ascii
      $a2 = "RtlGetCo" fullword ascii
      $a3 = "hutils" fullword ascii

      $b1 = "%USERPROFILE%\\System" fullword ascii
      $b2 = "msid.dat" fullword ascii
      $b3 = "DRIVE_REMOTE" fullword wide
      $b4 = "%s%s%s%s%s%s%s%s%s%s%s%s" fullword ascii
      $b5 = "jcbhe.asp" fullword ascii
      $b6 = "edset.asp" fullword ascii
      $b7 = "bxcve.asp" fullword ascii
      $b8 = "hcvery.php" fullword ascii
      $b9 = "ynhkef.php" fullword ascii
      $b10 = "dkgwey.php" fullword ascii
   condition:
      uint16(0) == 0x5a4d and filesize < 300KB and (
         pe.imphash() == "088382f4887e3b2c4bd5157f2d72b618" or
         all of ($a*) or