rule win_thunderx_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        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 = "20230124"
        malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686"
        malpedia_version = "20230125"
        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 = { c745fc01000000 50 ff15???????? 50 ff15???????? 85c0 741b }
            // n = 7, score = 200
            //   c745fc01000000       | mov                 dword ptr [ebp - 4], 1
            //   50                   | push                eax
            //   ff15????????         |                     
            //   50                   | push                eax
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   741b                 | je                  0x1d

        $sequence_1 = { 8bce e8???????? eb0c 83fb03 7570 8bce }
            // n = 6, score = 200
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     
            //   eb0c                 | jmp                 0xe
            //   83fb03               | cmp                 ebx, 3
            //   7570                 | jne                 0x72
            //   8bce                 | mov                 ecx, esi

        $sequence_2 = { 8d4db0 e8???????? 8bc7 e8???????? c3 55 8bec }
            // n = 7, score = 200
            //   8d4db0               | lea                 ecx, [ebp - 0x50]
            //   e8????????           |                     
            //   8bc7                 | mov                 eax, edi
            //   e8????????           |                     
            //   c3                   | ret                 
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp

        $sequence_3 = { 33c8 894da8 8b45a0 03c1 6a12 50 }
            // n = 6, score = 200
            //   33c8                 | xor                 ecx, eax
            //   894da8               | mov                 dword ptr [ebp - 0x58], ecx
            //   8b45a0               | mov                 eax, dword ptr [ebp - 0x60]
            //   03c1                 | add                 eax, ecx
            //   6a12                 | push                0x12
            //   50                   | push                eax

        $sequence_4 = { 3145b4 83c440 8b4598 0345b8 }
            // n = 4, score = 200
            //   3145b4               | xor                 dword ptr [ebp - 0x4c], eax
            //   83c440               | add                 esp, 0x40
            //   8b4598               | mov                 eax, dword ptr [ebp - 0x68]
            //   0345b8               | add                 eax, dword ptr [ebp - 0x48]

        $sequence_5 = { ff35???????? ff15???????? 8b75ec 85f6 74d3 85c0 74cf }
            // n = 7, score = 200
            //   ff35????????         |                     
            //   ff15????????         |                     
            //   8b75ec               | mov                 esi, dword ptr [ebp - 0x14]
            //   85f6                 | test                esi, esi
            //   74d3                 | je                  0xffffffd5
            //   85c0                 | test                eax, eax
            //   74cf                 | je                  0xffffffd1

        $sequence_6 = { 85d2 7417 8d45bc 2bf0 }
            // n = 4, score = 200
            //   85d2                 | test                edx, edx
            //   7417                 | je                  0x19
            //   8d45bc               | lea                 eax, [ebp - 0x44]
            //   2bf0                 | sub                 esi, eax

        $sequence_7 = { 50 ff15???????? 8d8d84fbffff 8985b8fbffff e8???????? 6887690000 }
            // n = 6, score = 200
            //   50                   | push                eax
            //   ff15????????         |                     
            //   8d8d84fbffff         | lea                 ecx, [ebp - 0x47c]
            //   8985b8fbffff         | mov                 dword ptr [ebp - 0x448], eax
            //   e8????????           |                     
            //   6887690000           | push                0x6987

        $sequence_8 = { c1f906 6bf638 8b0c8d701b4200 80643128fd 5f }
            // n = 5, score = 200
            //   c1f906               | sar                 ecx, 6
            //   6bf638               | imul                esi, esi, 0x38
            //   8b0c8d701b4200       | mov                 ecx, dword ptr [ecx*4 + 0x421b70]
            //   80643128fd           | and                 byte ptr [ecx + esi + 0x28], 0xfd
            //   5f                   | pop                 edi

        $sequence_9 = { c1fa06 83e03f 6bf838 8955f8 8b1495701b4200 897df4 }
            // n = 6, score = 200
            //   c1fa06               | sar                 edx, 6
            //   83e03f               | and                 eax, 0x3f
            //   6bf838               | imul                edi, eax, 0x38
            //   8955f8               | mov                 dword ptr [ebp - 8], edx
            //   8b1495701b4200       | mov                 edx, dword ptr [edx*4 + 0x421b70]
            //   897df4               | mov                 dword ptr [ebp - 0xc], edi

    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 )
}