rule win_thunderx_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-04-08"
        version = "1"
        description = "Detects win.thunderx."
        info = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.6.0"
        signator_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.thunderx"
        malpedia_rule_date = "20220405"
        malpedia_hash = "ecd38294bd47d5589be5cd5490dc8bb4804afc2a"
        malpedia_version = "20220411"
        malpedia_license = "CC BY-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    /* DISCLAIMER
     * The strings used in this rule have been automatically selected from the
     * disassembly of memory dumps and unpacked files, using YARA-Signator.
     * The code and documentation is published here:
     * https://github.com/fxb-cocacoding/yara-signator
     * As Malpedia is used as data source, please note that for a given
     * number of families, only single samples are documented.
     * This likely impacts the degree of generalization these rules will offer.
     * Take the described generation method also into consideration when you
     * apply the rules in your use cases and assign them confidence levels.
     */


    strings:
        $sequence_0 = { 8bcb 8b5510 66397dfc 741b 83fa01 740d }
            // n = 6, score = 200
            //   8bcb                 | mov                 ecx, ebx
            //   8b5510               | mov                 edx, dword ptr [ebp + 0x10]
            //   66397dfc             | cmp                 word ptr [ebp - 4], di
            //   741b                 | je                  0x1d
            //   83fa01               | cmp                 edx, 1
            //   740d                 | je                  0xf

        $sequence_1 = { 50 e8???????? 8b4d8c 33c8 8b4590 03c1 894d8c }
            // n = 7, score = 200
            //   50                   | push                eax
            //   e8????????           |                     
            //   8b4d8c               | mov                 ecx, dword ptr [ebp - 0x74]
            //   33c8                 | xor                 ecx, eax
            //   8b4590               | mov                 eax, dword ptr [ebp - 0x70]
            //   03c1                 | add                 eax, ecx
            //   894d8c               | mov                 dword ptr [ebp - 0x74], ecx

        $sequence_2 = { 57 53 56 897e10 e8???????? 83c40c 881c37 }
            // n = 7, score = 200
            //   57                   | push                edi
            //   53                   | push                ebx
            //   56                   | push                esi
            //   897e10               | mov                 dword ptr [esi + 0x10], edi
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   881c37               | mov                 byte ptr [edi + esi], bl

        $sequence_3 = { 8a8748054200 08441619 42 0fb64101 3bd0 76e5 83c102 }
            // n = 7, score = 200
            //   8a8748054200         | mov                 al, byte ptr [edi + 0x420548]
            //   08441619             | or                  byte ptr [esi + edx + 0x19], al
            //   42                   | inc                 edx
            //   0fb64101             | movzx               eax, byte ptr [ecx + 1]
            //   3bd0                 | cmp                 edx, eax
            //   76e5                 | jbe                 0xffffffe7
            //   83c102               | add                 ecx, 2

        $sequence_4 = { 53 6a00 e8???????? 59 50 e8???????? 33db }
            // n = 7, score = 200
            //   53                   | push                ebx
            //   6a00                 | push                0
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   50                   | push                eax
            //   e8????????           |                     
            //   33db                 | xor                 ebx, ebx

        $sequence_5 = { 8d5110 3b02 7714 83791408 7202 }
            // n = 5, score = 200
            //   8d5110               | lea                 edx, dword ptr [ecx + 0x10]
            //   3b02                 | cmp                 eax, dword ptr [edx]
            //   7714                 | ja                  0x16
            //   83791408             | cmp                 dword ptr [ecx + 0x14], 8
            //   7202                 | jb                  4

        $sequence_6 = { 8bf0 56 e8???????? 6bce18 8bd8 891f 895f04 }
            // n = 7, score = 200
            //   8bf0                 | mov                 esi, eax
            //   56                   | push                esi
            //   e8????????           |                     
            //   6bce18               | imul                ecx, esi, 0x18
            //   8bd8                 | mov                 ebx, eax
            //   891f                 | mov                 dword ptr [edi], ebx
            //   895f04               | mov                 dword ptr [edi + 4], ebx

        $sequence_7 = { 33c8 8b4598 03c1 894d8c 6a0d 50 e8???????? }
            // n = 7, score = 200
            //   33c8                 | xor                 ecx, eax
            //   8b4598               | mov                 eax, dword ptr [ebp - 0x68]
            //   03c1                 | add                 eax, ecx
            //   894d8c               | mov                 dword ptr [ebp - 0x74], ecx
            //   6a0d                 | push                0xd
            //   50                   | push                eax
            //   e8????????           |                     

        $sequence_8 = { 50 e8???????? 8b4da0 33c8 8b45a4 03c1 894da0 }
            // n = 7, score = 200
            //   50                   | push                eax
            //   e8????????           |                     
            //   8b4da0               | mov                 ecx, dword ptr [ebp - 0x60]
            //   33c8                 | xor                 ecx, eax
            //   8b45a4               | mov                 eax, dword ptr [ebp - 0x5c]
            //   03c1                 | add                 eax, ecx
            //   894da0               | mov                 dword ptr [ebp - 0x60], ecx

        $sequence_9 = { 8b75fc 51 57 894e18 }
            // n = 4, score = 200
            //   8b75fc               | mov                 esi, dword ptr [ebp - 4]
            //   51                   | push                ecx
            //   57                   | push                edi
            //   894e18               | mov                 dword ptr [esi + 0x18], ecx

    condition:
        7 of them and filesize < 319488
}

import "pe"

rule win_thunderx_w0 {
   meta:
      description = "Rule to dettect tthe ThunderX ransomware family"
      author = "Christiaan Beek @ McAfee ATR team"
      date = "2020-09-14"
      rule_version = "v1"
      malware_type = "ransomware"
      malware_family = "Ransomware:W32/ThunderX"
      actor_type = "Cybercrime"
      actor_group = "Unknown"
      hash1 = "7bab5dedef124803668580a59b6bf3c53cc31150d19591567397bbc131b9ccb6"
      hash2 = "0fbfdb8340108fafaca4c5ff4d3c9f9a2296efeb9ae89fcd9210e3d4c7239666"
      hash3 = "7527459500109b3bb48665236c5c5cb2ec71ba789867ad2b6417b38b9a46615e"
      source = "https://github.com/advanced-threat-research/Yara-Rules/blob/master/ransomware/Ransom_ThunderX.yar"
      malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.thunderx"
      malpedia_rule_date = "20200915"
      malpedia_hash = ""
      malpedia_version = "20200915"
      malpedia_license = "CC BY-SA 4.0"
      malpedia_sharing = "TLP:WHITE"

   strings:
   
      $pattern1 = "626364656469742E657865202F736574207B64656661756C747D20626F6F74737461747573706F6C6963792069676E6F7265616C6C6661696C75726573" 
     
      $s3 = "776261646D696E2044454C4554452053595354454D53544154454241434B5550202D64656C6574654F6C64657374" ascii
      $s4 = "626364656469742E657865202F736574207B64656661756C747D207265636F76657279656E61626C6564204E6F" ascii 
      $s5 = "776261646D696E2044454C4554452053595354454D53544154454241434B5550" ascii 
      $s6 = "433A5C50726F6772616D2046696C65732028783836295C4D6963726F736F66742053514C20536572766572" ascii 
      $s7 = "476C6F62616C5C33353335354641352D303745392D343238422D423541352D314338384341423242343838" ascii 
      $s8 = "433A5C50726F6772616D2046696C65735C4D6963726F736F66742053514C20536572766572" ascii 
      $s9 = "76737361646D696E2E6578652044656C65746520536861646F7773202F416C6C202F5175696574" ascii 
      $s10 = "776D69632E65786520534841444F57434F5059202F6E6F696E746572616374697665" ascii 
      $s11 = "534F4654574152455C4D6963726F736F66745C45524944" ascii 
      $s12 = "AppPolicyGetProcessTerminationMethod" fullword ascii
      $s13 = "7B5041545445524E5F49447D" ascii 
      $s14 = "726561646D652E747874" ascii 
      $s15 = "226E6574776F726B223A22" ascii 
      $s16 = "227375626964223A22" ascii 
      $s17 = "226C616E67223A22" ascii 
      $s18 = "22657874223A22" ascii 
      $s19 = "69642E6B6579" ascii 
      $s20 = "7B5549447D" ascii 

      $seq0 = { eb 34 66 0f 12 0d 10 c4 41 00 f2 0f 59 c1 ba cc }
      $seq1 = { 6a 07 50 e8 51 ff ff ff 8d 86 d0 }
      $seq2 = { ff 15 34 81 41 00 eb 15 83 f8 fc 75 10 8b 45 f4 }
   condition:
      ( uint16(0) == 0x5a4d and filesize < 400KB and pe.imphash() == "ea7e408cd2a264fd13492973e97d8d70" and $pattern1 and 4 of them ) and all of ($seq*) or ( all of them )
}