rule win_ryuk_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2020-10-14"
        version = "1"
        description = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.5.0"
        tool_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.ryuk"
        malpedia_rule_date = "20201014"
        malpedia_hash = "a7e3bd57eaf12bf3ea29a863c041091ba3af9ac9"
        malpedia_version = "20201014"
        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 = { e8???????? e8???????? b9e8030000 ff15???????? }
            // n = 4, score = 700
            //   e8????????           |                     
            //   e8????????           |                     
            //   b9e8030000           | mov                 ecx, 0x3e8
            //   ff15????????         |                     

        $sequence_1 = { ff15???????? b803000000 eb05 b805000000 }
            // n = 4, score = 700
            //   ff15????????         |                     
            //   b803000000           | mov                 eax, 3
            //   eb05                 | jmp                 7
            //   b805000000           | mov                 eax, 5

        $sequence_2 = { 4983c8ff e8???????? 488bc3 4883c430 5b c3 48895c2408 }
            // n = 7, score = 600
            //   4983c8ff             | xor                 eax, eax
            //   e8????????           |                     
            //   488bc3               | xor                 edx, edx
            //   4883c430             | dec                 ecx
            //   5b                   | or                  eax, 0xffffffff
            //   c3                   | dec                 eax
            //   48895c2408           | mov                 eax, ebx

        $sequence_3 = { 488b7c2408 498bc1 c3 4053 4883ec20 8bc1 498bd8 }
            // n = 7, score = 600
            //   488b7c2408           | dec                 eax
            //   498bc1               | add                 esp, 0x30
            //   c3                   | pop                 ebx
            //   4053                 | ret                 
            //   4883ec20             | dec                 eax
            //   8bc1                 | mov                 dword ptr [esp + 8], ebx
            //   498bd8               | dec                 eax

        $sequence_4 = { b809000000 e9???????? 4533c9 4533c0 33d2 }
            // n = 5, score = 600
            //   b809000000           | mov                 eax, 9
            //   e9????????           |                     
            //   4533c9               | inc                 ebp
            //   4533c0               | xor                 ecx, ecx
            //   33d2                 | inc                 ebp

        $sequence_5 = { 68???????? 6a01 6a00 6814010000 }
            // n = 4, score = 600
            //   68????????           |                     
            //   6a01                 | push                1
            //   6a00                 | push                0
            //   6814010000           | push                0x114

        $sequence_6 = { 4883c428 c3 48895c2408 57 4883ec30 8364242000 }
            // n = 6, score = 600
            //   4883c428             | mov                 edi, dword ptr [esp + 8]
            //   c3                   | dec                 ecx
            //   48895c2408           | mov                 eax, ecx
            //   57                   | ret                 
            //   4883ec30             | inc                 eax
            //   8364242000           | push                ebx

        $sequence_7 = { ff15???????? 85c0 7508 6a01 ff15???????? 68???????? 6a01 }
            // n = 7, score = 500
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7508                 | jne                 0xa
            //   6a01                 | push                1
            //   ff15????????         |                     
            //   68????????           |                     
            //   6a01                 | push                1

        $sequence_8 = { 750c 80780345 7506 80780453 }
            // n = 4, score = 500
            //   750c                 | add                 esp, 0x28
            //   80780345             | ret                 
            //   7506                 | dec                 eax
            //   80780453             | mov                 dword ptr [esp + 8], ebx

        $sequence_9 = { 2bc2 d1e8 03c2 c1e806 6bc05a }
            // n = 5, score = 500
            //   2bc2                 | mov                 edi, dword ptr [esp + 8]
            //   d1e8                 | dec                 ecx
            //   03c2                 | mov                 eax, ecx
            //   c1e806               | ret                 
            //   6bc05a               | inc                 eax

        $sequence_10 = { 33c9 ff15???????? 48897c2430 488d4c2440 c744242802000000 4533c9 }
            // n = 6, score = 500
            //   33c9                 | push                esi
            //   ff15????????         |                     
            //   48897c2430           | push                esi
            //   488d4c2440           | push                0x8000
            //   c744242802000000     | mov                 ecx, 0x3e8
            //   4533c9               | mov                 eax, 3

        $sequence_11 = { 488d4c2440 c744242802000000 4533c9 4533c0 c744242002000000 ba000000c0 ff15???????? }
            // n = 7, score = 500
            //   488d4c2440           | pop                 ebp
            //   c744242802000000     | ret                 
            //   4533c9               | push                8
            //   4533c0               | ret                 4
            //   c744242002000000     | mov                 edi, edi
            //   ba000000c0           | push                ebp
            //   ff15????????         |                     

        $sequence_12 = { 33c9 ff15???????? 448b442468 33d2 }
            // n = 4, score = 500
            //   33c9                 | jmp                 7
            //   ff15????????         |                     
            //   448b442468           | mov                 eax, 5
            //   33d2                 | dec                 eax

        $sequence_13 = { 751d 803845 7518 80780152 7512 }
            // n = 5, score = 500
            //   751d                 | mov                 eax, 0xffff
            //   803845               | push                ebx
            //   7518                 | test                eax, eax
            //   80780152             | jne                 0x58
            //   7512                 | push                ebx

        $sequence_14 = { ff15???????? 83f820 7510 488bcb ff15???????? b802000000 }
            // n = 6, score = 500
            //   ff15????????         |                     
            //   83f820               | test                eax, eax
            //   7510                 | jne                 0x6c
            //   488bcb               | push                0x28
            //   ff15????????         |                     
            //   b802000000           | xor                 esi, esi

        $sequence_15 = { 7407 48 85c0 7ff0 }
            // n = 4, score = 400
            //   7407                 | je                  9
            //   48                   | dec                 eax
            //   85c0                 | test                eax, eax
            //   7ff0                 | jg                  0xfffffff2

        $sequence_16 = { 0f9fc0 5d c3 8bff 55 8bec 8b4508 }
            // n = 7, score = 400
            //   0f9fc0               | shr                 eax, 6
            //   5d                   | imul                eax, eax, 0x5a
            //   c3                   | shr                 eax, 1
            //   8bff                 | add                 eax, edx
            //   55                   | shr                 eax, 6
            //   8bec                 | imul                eax, eax, 0x5a
            //   8b4508               | mov                 eax, ecx

        $sequence_17 = { 746c e8???????? 488d0d63080000 e8???????? e8???????? 8bc8 }
            // n = 6, score = 400
            //   746c                 | or                  eax, 0xffffffff
            //   e8????????           |                     
            //   488d0d63080000       | dec                 eax
            //   e8????????           |                     
            //   e8????????           |                     
            //   8bc8                 | mov                 eax, ebx

        $sequence_18 = { b901000000 8903 e8???????? 84c0 746c e8???????? 488d0d63080000 }
            // n = 7, score = 400
            //   b901000000           | dec                 eax
            //   8903                 | add                 eax, 0x20
            //   e8????????           |                     
            //   84c0                 | dec                 eax
            //   746c                 | add                 esp, 0x28
            //   e8????????           |                     
            //   488d0d63080000       | ret                 

        $sequence_19 = { ff750c ff7508 e8???????? 5e 5d c3 6a08 }
            // n = 7, score = 400
            //   ff750c               | dec                 ecx
            //   ff7508               | mov                 eax, ecx
            //   e8????????           |                     
            //   5e                   | ret                 
            //   5d                   | inc                 eax
            //   c3                   | push                ebx
            //   6a08                 | dec                 eax

        $sequence_20 = { e9???????? 6a04 6800100000 6810270000 }
            // n = 4, score = 400
            //   e9????????           |                     
            //   6a04                 | push                4
            //   6800100000           | push                0x1000
            //   6810270000           | push                0x2710

        $sequence_21 = { c20400 8bff 55 8bec b8ffff0000 83ec18 }
            // n = 6, score = 400
            //   c20400               | ret                 
            //   8bff                 | dec                 eax
            //   55                   | mov                 dword ptr [esp + 8], ebx
            //   8bec                 | dec                 eax
            //   b8ffff0000           | mov                 dword ptr [esp + 0x10], ebp
            //   83ec18               | ret                 

        $sequence_22 = { 8d7602 6685c9 75f1 5e 5d c3 8bff }
            // n = 7, score = 400
            //   8d7602               | mov                 dword ptr [esp + 8], ebx
            //   6685c9               | push                edi
            //   75f1                 | dec                 eax
            //   5e                   | sub                 esp, 0x30
            //   5d                   | sub                 eax, edx
            //   c3                   | shr                 eax, 1
            //   8bff                 | add                 eax, edx

        $sequence_23 = { 57 53 ff15???????? 85c0 7530 }
            // n = 5, score = 300
            //   57                   | push                edi
            //   53                   | push                ebx
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7530                 | jne                 0x32

        $sequence_24 = { bb???????? 56 7538 68???????? }
            // n = 4, score = 300
            //   bb????????           |                     
            //   56                   | push                esi
            //   7538                 | jne                 0x3a
            //   68????????           |                     

        $sequence_25 = { 6a00 ff15???????? 6a00 6a02 6a03 6a00 }
            // n = 6, score = 300
            //   6a00                 | mul                 ecx
            //   ff15????????         |                     
            //   6a00                 | mov                 eax, ecx
            //   6a02                 | sub                 eax, edx
            //   6a03                 | shr                 eax, 1
            //   6a00                 | add                 eax, edx

        $sequence_26 = { 6a08 6a18 68???????? 68???????? 68???????? ff15???????? 85c0 }
            // n = 7, score = 300
            //   6a08                 | dec                 eax
            //   6a18                 | mov                 ebx, eax
            //   68????????           |                     
            //   68????????           |                     
            //   68????????           |                     
            //   ff15????????         |                     
            //   85c0                 | cmp                 eax, 0x20

        $sequence_27 = { 85c0 7530 6a28 56 68???????? }
            // n = 5, score = 300
            //   85c0                 | test                eax, eax
            //   7530                 | jne                 0x32
            //   6a28                 | push                0x28
            //   56                   | push                esi
            //   68????????           |                     

        $sequence_28 = { ff15???????? 56 ff15???????? be14010000 }
            // n = 4, score = 300
            //   ff15????????         |                     
            //   56                   | push                esi
            //   ff15????????         |                     
            //   be14010000           | mov                 esi, 0x114

        $sequence_29 = { 6a0a c1e818 51 50 }
            // n = 4, score = 200
            //   6a0a                 | push                0xa
            //   c1e818               | shr                 eax, 0x18
            //   51                   | push                ecx
            //   50                   | push                eax

        $sequence_30 = { ff15???????? b809000000 5f 5e }
            // n = 4, score = 200
            //   ff15????????         |                     
            //   b809000000           | mov                 eax, 9
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi

        $sequence_31 = { 57 ff15???????? b80c000000 5f }
            // n = 4, score = 200
            //   57                   | push                edi
            //   ff15????????         |                     
            //   b80c000000           | mov                 eax, 0xc
            //   5f                   | pop                 edi

        $sequence_32 = { 8d0c49 c1e103 51 6a00 }
            // n = 4, score = 200
            //   8d0c49               | lea                 ecx, [ecx + ecx*2]
            //   c1e103               | shl                 ecx, 3
            //   51                   | push                ecx
            //   6a00                 | push                0

        $sequence_33 = { 2bf0 33c0 66890473 83ffff }
            // n = 4, score = 200
            //   2bf0                 | sub                 esi, eax
            //   33c0                 | xor                 eax, eax
            //   66890473             | mov                 word ptr [ebx + esi*2], ax
            //   83ffff               | cmp                 edi, -1

        $sequence_34 = { 83c001 8945b4 c745b000000000 8b4dd4 8b5110 }
            // n = 5, score = 200
            //   83c001               | ret                 4
            //   8945b4               | mov                 edi, edi
            //   c745b000000000       | push                ebp
            //   8b4dd4               | mov                 ebp, esp
            //   8b5110               | mov                 eax, 0xffff

        $sequence_35 = { 6a00 ffd6 6800400000 6a40 }
            // n = 4, score = 200
            //   6a00                 | push                0
            //   ffd6                 | call                esi
            //   6800400000           | push                0x4000
            //   6a40                 | push                0x40

        $sequence_36 = { eb03 50 6af6 ff15???????? 8b04bd884c4400 834c0318ff }
            // n = 6, score = 100
            //   eb03                 | jmp                 5
            //   50                   | push                eax
            //   6af6                 | push                -0xa
            //   ff15????????         |                     
            //   8b04bd884c4400       | mov                 eax, dword ptr [edi*4 + 0x444c88]
            //   834c0318ff           | or                  dword ptr [ebx + eax + 0x18], 0xffffffff

        $sequence_37 = { 6a0a 8bf8 ff15???????? 83feff 7508 3bfe }
            // n = 6, score = 100
            //   6a0a                 | push                0xa
            //   8bf8                 | mov                 edi, eax
            //   ff15????????         |                     
            //   83feff               | cmp                 esi, -1
            //   7508                 | jne                 0xa
            //   3bfe                 | cmp                 edi, esi

    condition:
        7 of them and filesize < 7450624
}