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
      )
}

rule APT_MAL_REvil_Kaseya_Jul21_2 {
   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 = "0496ca57e387b10dfdac809de8a4e039f68e8d66535d5d19ec76d39f7d0a4402"
      hash2 = "8dd620d9aeb35960bb766458c8890ede987c33d239cf730f93fe49d90ae759dd"
      hash3 = "cc0cdc6a3d843e22c98170713abf1d6ae06e8b5e34ed06ac3159adafe85e3bd6"
      hash4 = "d5ce6f36a06b0dc8ce8e7e2c9a53e66094c2adfc93cfac61dd09efe9ac45a75f"
      hash5 = "d8353cfc5e696d3ae402c7c70565c1e7f31e49bcf74a6e12e5ab044f306b4b20"
      hash6 = "e2a24ab94f865caeacdf2c3ad015f31f23008ac6db8312c2cbfb32e4a5466ea2"
      id = "38b168d4-e761-544e-9859-eb155bbfe54a"
   strings:
      $opa1 = { 8b 4d fc 83 c1 01 89 4d fc 81 7d f0 ff 00 00 00 77 1? ba 01 00 00 00 6b c2 00 8b 4d 08 }
      $opa2 = { 89 45 f0 8b 4d fc 83 c1 01 89 4d fc 81 7d f0 ff 00 00 00 77 1? ba 01 00 00 00 6b c2 00 }
      $opa3 = { 83 c1 01 89 4d fc 81 7d f0 ff 00 00 00 77 1? ba 01 00 00 00 6b c2 00 8b 4d 08 0f b6 14 01 }
      $opa4 = { 89 45 f4 8b 0d ?? ?0 07 10 89 4d f8 8b 15 ?? ?1 07 10 89 55 fc ff 75 fc ff 75 f8 ff 55 f4 }

      $opb1 = { 18 00 10 bd 18 00 10 bd 18 00 10 0e 19 00 10 cc cc cc }
      $opb2 = { 18 00 10 0e 19 00 10 cc cc cc cc 8b 44 24 04 }
      $opb3 = { 10 c4 18 00 10 bd 18 00 10 bd 18 00 10 0e 19 00 10 cc cc }
   condition:
      uint16(0) == 0x5a4d and
      filesize < 3000KB and ( 2 of ($opa*) or 3 of them )
}

rule MAL_RANSOM_REvil_Oct20_1 {
   meta:
      description = "Detects REvil ransomware"
      author = "Florian Roth (Nextron Systems)"
      reference = "Internal Research"
      date = "2020-10-13"
      hash1 = "5966c25dc1abcec9d8603b97919db57aac019e5358ee413957927d3c1790b7f4"
      hash2 = "f66027faea8c9e0ff29a31641e186cbed7073b52b43933ba36d61e8f6bce1ab5"
      hash3 = "f6857748c050655fb3c2192b52a3b0915f3f3708cd0a59bbf641d7dd722a804d"
      hash4 = "fc26288df74aa8046b4761f8478c52819e0fca478c1ab674da7e1d24e1cfa501"
      id = "0c85a2cc-3487-577f-bd12-e3effd8fc811"
   strings:
      $op1 = { 0f 8c 74 ff ff ff 33 c0 5f 5e 5b 8b e5 5d c3 8b }
      $op2 = { 8d 85 68 ff ff ff 50 e8 2a fe ff ff 8d 85 68 ff }
      $op3 = { 89 4d f4 8b 4e 0c 33 4e 34 33 4e 5c 33 8e 84 }
      $op4 = { 8d 85 68 ff ff ff 50 e8 05 06 00 00 8d 85 68 ff }
      $op5 = { 8d 85 68 ff ff ff 56 57 ff 75 0c 50 e8 2f }
   condition:
      uint16(0) == 0x5a4d and
      filesize < 400KB and
      2 of them or 4 of them
}