APT_MAL_REvil_Kaseya_Jul21_1

rule APT_MAL_REvil_Kaseya_Jul21_1 {
   meta:
      description = "Detects malware used in the Kaseya supply chain attack"
      author = "Florian Roth (Nextron Systems)"
      reference = "https://doublepulsar.com/kaseya-supply-chain-attack-delivers-mass-ransomware-event-to-us-companies-76e4ec6ec64b"
      date = "2021-07-02"
      hash1 = "1fe9b489c25bb23b04d9996e8107671edee69bd6f6def2fe7ece38a0fb35f98e"
      hash2 = "aae6e388e774180bc3eb96dad5d5bfefd63d0eb7124d68b6991701936801f1c7"
      hash3 = "dc6b0e8c1e9c113f0364e1c8370060dee3fcbe25b667ddeca7623a95cd21411f"
      hash4 = "df2d6ef0450660aaae62c429610b964949812df2da1c57646fc29aa51c3f031e"
      id = "7356f4ea-183f-52ec-a167-fc16b8bfb55a"
   strings:
      $s1 = "Mpsvc.dll" wide fullword
      $s2 = ":0:4:8:<:@:D:H:L:P:T:X:\\:`:d:h:l:p:t:x:H<L<P<\\<`<" ascii fullword

      $op1 = { 40 87 01 c3 6a 08 68 f8 0e 41 00 e8 ae db ff ff be 80 25 41 00 39 35 ?? 32 41 00 }
      $op2 = { 8b 40 04 2b c2 c1 f8 02 3b c8 0f 84 56 ff ff ff 68 15 50 40 00 2b c1 6a 04 }
      $op3 = { 74 73 db e2 e8 ad 07 00 00 68 60 1a 40 00 e8 8f 04 00 00 e8 3a 05 00 00 50 e8 25 26 00 00 }
      $op4 = { 75 05 8b 45 fc eb 4c c7 45 f8 00 00 00 00 6a 00 8d 45 f0 50 8b 4d 0c }
      $op5 = { 83 7d 0c 00 75 05 8b 45 fc eb 76 6a 00 68 80 00 00 00 6a 01 6a 00 }
   condition:
      uint16(0) == 0x5a4d and
      filesize < 3000KB and
      (
         pe.imphash() == "c36dcd2277c4a707a1a645d0f727542a" or
         2 of them
      )
}