rule win_wannacryptor_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-04-08"
        version = "1"
        description = "Detects win.wannacryptor."
        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.wannacryptor"
        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 = { 56 57 33f6 8d7904 8bc6 68000000f0 }
            // n = 6, score = 600
            //   56                   | push                esi
            //   57                   | push                edi
            //   33f6                 | xor                 esi, esi
            //   8d7904               | lea                 edi, dword ptr [ecx + 4]
            //   8bc6                 | mov                 eax, esi
            //   68000000f0           | push                0xf0000000

        $sequence_1 = { 8b5500 8d442414 6a02 50 }
            // n = 4, score = 600
            //   8b5500               | mov                 edx, dword ptr [ebp]
            //   8d442414             | lea                 eax, dword ptr [esp + 0x14]
            //   6a02                 | push                2
            //   50                   | push                eax

        $sequence_2 = { 7e0a 6a64 ff15???????? 33ed }
            // n = 4, score = 600
            //   7e0a                 | jle                 0xc
            //   6a64                 | push                0x64
            //   ff15????????         |                     
            //   33ed                 | xor                 ebp, ebp

        $sequence_3 = { c1fa08 8810 40 8808 40 eb23 }
            // n = 6, score = 600
            //   c1fa08               | sar                 edx, 8
            //   8810                 | mov                 byte ptr [eax], dl
            //   40                   | inc                 eax
            //   8808                 | mov                 byte ptr [eax], cl
            //   40                   | inc                 eax
            //   eb23                 | jmp                 0x25

        $sequence_4 = { 57 8bcd e8???????? 8b4e74 }
            // n = 4, score = 600
            //   57                   | push                edi
            //   8bcd                 | mov                 ecx, ebp
            //   e8????????           |                     
            //   8b4e74               | mov                 ecx, dword ptr [esi + 0x74]

        $sequence_5 = { 81ec08020000 53 8b9c2410020000 85db }
            // n = 4, score = 600
            //   81ec08020000         | sub                 esp, 0x208
            //   53                   | push                ebx
            //   8b9c2410020000       | mov                 ebx, dword ptr [esp + 0x210]
            //   85db                 | test                ebx, ebx

        $sequence_6 = { 8b4604 6a00 8d54240f 57 52 50 ff15???????? }
            // n = 7, score = 600
            //   8b4604               | mov                 eax, dword ptr [esi + 4]
            //   6a00                 | push                0
            //   8d54240f             | lea                 edx, dword ptr [esp + 0xf]
            //   57                   | push                edi
            //   52                   | push                edx
            //   50                   | push                eax
            //   ff15????????         |                     

        $sequence_7 = { 50 ff15???????? 8b4c2408 8b54240c 894e50 57 }
            // n = 6, score = 600
            //   50                   | push                eax
            //   ff15????????         |                     
            //   8b4c2408             | mov                 ecx, dword ptr [esp + 8]
            //   8b54240c             | mov                 edx, dword ptr [esp + 0xc]
            //   894e50               | mov                 dword ptr [esi + 0x50], ecx
            //   57                   | push                edi

        $sequence_8 = { 03c2 8b16 c1f805 0faff8 897e04 8b4160 03c2 }
            // n = 7, score = 600
            //   03c2                 | add                 eax, edx
            //   8b16                 | mov                 edx, dword ptr [esi]
            //   c1f805               | sar                 eax, 5
            //   0faff8               | imul                edi, eax
            //   897e04               | mov                 dword ptr [esi + 4], edi
            //   8b4160               | mov                 eax, dword ptr [ecx + 0x60]
            //   03c2                 | add                 eax, edx

        $sequence_9 = { c744244817406700 894c244c 896c2450 89542454 e8???????? 8b5658 8b4008 }
            // n = 7, score = 600
            //   c744244817406700     | mov                 dword ptr [esp + 0x48], 0x674017
            //   894c244c             | mov                 dword ptr [esp + 0x4c], ecx
            //   896c2450             | mov                 dword ptr [esp + 0x50], ebp
            //   89542454             | mov                 dword ptr [esp + 0x54], edx
            //   e8????????           |                     
            //   8b5658               | mov                 edx, dword ptr [esi + 0x58]
            //   8b4008               | mov                 eax, dword ptr [eax + 8]

    condition:
        7 of them and filesize < 540672
}