rule win_thunderx_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        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 = "20260422"
        malpedia_hash = "a182e35da64e6d71cb55f125c4d4225196523f14"
        malpedia_version = "20260504"
        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 = { 56 8b7508 8d5602 668b06 83c602 6685c0 }
            // n = 6, score = 200
            //   56                   | push                esi
            //   8b7508               | mov                 esi, dword ptr [ebp + 8]
            //   8d5602               | lea                 edx, [esi + 2]
            //   668b06               | mov                 ax, word ptr [esi]
            //   83c602               | add                 esi, 2
            //   6685c0               | test                ax, ax

        $sequence_1 = { 8b4590 03c1 894d8c 6a0d 50 e8???????? }
            // n = 6, score = 200
            //   8b4590               | mov                 eax, dword ptr [ebp - 0x70]
            //   03c1                 | add                 eax, ecx
            //   894d8c               | mov                 dword ptr [ebp - 0x74], ecx
            //   6a0d                 | push                0xd
            //   50                   | push                eax
            //   e8????????           |                     

        $sequence_2 = { 50 e8???????? 8d4dd4 e8???????? 8d4dbc e8???????? 8bc3 }
            // n = 7, score = 200
            //   50                   | push                eax
            //   e8????????           |                     
            //   8d4dd4               | lea                 ecx, [ebp - 0x2c]
            //   e8????????           |                     
            //   8d4dbc               | lea                 ecx, [ebp - 0x44]
            //   e8????????           |                     
            //   8bc3                 | mov                 eax, ebx

        $sequence_3 = { eb02 33db 8ac3 e8???????? c3 55 8bec }
            // n = 7, score = 200
            //   eb02                 | jmp                 4
            //   33db                 | xor                 ebx, ebx
            //   8ac3                 | mov                 al, bl
            //   e8????????           |                     
            //   c3                   | ret                 
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp

        $sequence_4 = { 8945f0 e8???????? 8bf8 6bc61c 8b750c 56 897df8 }
            // n = 7, score = 200
            //   8945f0               | mov                 dword ptr [ebp - 0x10], eax
            //   e8????????           |                     
            //   8bf8                 | mov                 edi, eax
            //   6bc61c               | imul                eax, esi, 0x1c
            //   8b750c               | mov                 esi, dword ptr [ebp + 0xc]
            //   56                   | push                esi
            //   897df8               | mov                 dword ptr [ebp - 8], edi

        $sequence_5 = { 6a00 51 ff35???????? b8???????? 0f4305???????? 50 }
            // n = 6, score = 200
            //   6a00                 | push                0
            //   51                   | push                ecx
            //   ff35????????         |                     
            //   b8????????           |                     
            //   0f4305????????       |                     
            //   50                   | push                eax

        $sequence_6 = { a1???????? 33c4 8944241c 56 57 8bfa 8bf1 }
            // n = 7, score = 200
            //   a1????????           |                     
            //   33c4                 | xor                 eax, esp
            //   8944241c             | mov                 dword ptr [esp + 0x1c], eax
            //   56                   | push                esi
            //   57                   | push                edi
            //   8bfa                 | mov                 edi, edx
            //   8bf1                 | mov                 esi, ecx

        $sequence_7 = { 6a00 6a01 ff15???????? 8bf8 85ff 751a }
            // n = 6, score = 200
            //   6a00                 | push                0
            //   6a01                 | push                1
            //   ff15????????         |                     
            //   8bf8                 | mov                 edi, eax
            //   85ff                 | test                edi, edi
            //   751a                 | jne                 0x1c

        $sequence_8 = { 50 56 ffd7 85c0 7462 8b44240c }
            // n = 6, score = 200
            //   50                   | push                eax
            //   56                   | push                esi
            //   ffd7                 | call                edi
            //   85c0                 | test                eax, eax
            //   7462                 | je                  0x64
            //   8b44240c             | mov                 eax, dword ptr [esp + 0xc]

        $sequence_9 = { 894db0 8b048d701b4200 8975b4 8b440618 8b7514 03f2 }
            // n = 6, score = 200
            //   894db0               | mov                 dword ptr [ebp - 0x50], ecx
            //   8b048d701b4200       | mov                 eax, dword ptr [ecx*4 + 0x421b70]
            //   8975b4               | mov                 dword ptr [ebp - 0x4c], esi
            //   8b440618             | mov                 eax, dword ptr [esi + eax + 0x18]
            //   8b7514               | mov                 esi, dword ptr [ebp + 0x14]
            //   03f2                 | add                 esi, edx

    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 )
}