rule win_lowkey_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-04-08"
        version = "1"
        description = "Detects win.lowkey."
        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.lowkey"
        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 = { 85c0 7585 488bce ff15???????? 488bcb ff15???????? b801000000 }
            // n = 7, score = 100
            //   85c0                 | sub                 esp, 0x50
            //   7585                 | dec                 eax
            //   488bce               | xor                 eax, esp
            //   ff15????????         |                     
            //   488bcb               | dec                 eax
            //   ff15????????         |                     
            //   b801000000           | mov                 dword ptr [esp + 0x48], eax

        $sequence_1 = { 0f84a9000000 4c8d442440 488bc8 8d5708 ff15???????? 85c0 0f8487000000 }
            // n = 7, score = 100
            //   0f84a9000000         | je                  0x7bf
            //   4c8d442440           | dec                 eax
            //   488bc8               | mov                 ecx, eax
            //   8d5708               | dec                 eax
            //   ff15????????         |                     
            //   85c0                 | lea                 edx, dword ptr [0xb842]
            //   0f8487000000         | mov                 ecx, 0x18

        $sequence_2 = { 42387c3039 0f84bf000000 488d05e11b0300 4a8b0ce8 488d55f8 }
            // n = 5, score = 100
            //   42387c3039           | dec                 eax
            //   0f84bf000000         | mov                 ecx, dword ptr [edx + 0x50]
            //   488d05e11b0300       | dec                 eax
            //   4a8b0ce8             | add                 ecx, 0x28
            //   488d55f8             | ret                 

        $sequence_3 = { 488d542450 e8???????? 85c0 0f8486000000 448b442458 4585c0 741e }
            // n = 7, score = 100
            //   488d542450           | mov                 edx, dword ptr [ebx + 0x10]
            //   e8????????           |                     
            //   85c0                 | dec                 eax
            //   0f8486000000         | lea                 ecx, dword ptr [0x2334a]
            //   448b442458           | xor                 ebx, ebx
            //   4585c0               | jmp                 0xb2
            //   741e                 | dec                 eax

        $sequence_4 = { ff15???????? 85c0 743a 488b4c2430 448d4b10 48895c2428 4c8d442438 }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   85c0                 | mov                 ebx, eax
            //   743a                 | mov                 dword ptr [esp + 0x30], eax
            //   488b4c2430           | dec                 eax
            //   448d4b10             | mov                 esi, edx
            //   48895c2428           | inc                 esp
            //   4c8d442438           | mov                 dword ptr [esp + 0x30], esi

        $sequence_5 = { 488b542420 4c8d442430 41b904010000 488bcf ff15???????? 85c0 7413 }
            // n = 7, score = 100
            //   488b542420           | cmp                 eax, esp
            //   4c8d442430           | mov                 eax, ebp
            //   41b904010000         | dec                 ebp
            //   488bcf               | lea                 ecx, dword ptr [esp + 0x10]
            //   ff15????????         |                     
            //   85c0                 | dec                 esp
            //   7413                 | lea                 esi, dword ptr [0x12545]

        $sequence_6 = { e8???????? 488b9c24c8040000 4881c4a0040000 5f c3 48895c2418 }
            // n = 6, score = 100
            //   e8????????           |                     
            //   488b9c24c8040000     | mov                 ecx, dword ptr [esp + 0x2170]
            //   4881c4a0040000       | dec                 eax
            //   5f                   | xor                 ecx, esp
            //   c3                   | dec                 esp
            //   48895c2418           | lea                 ebx, dword ptr [esp + 0x2180]

        $sequence_7 = { 48898560460000 4533f6 4c89a424a0470000 418bfe 4c89bc24b0470000 4c8d3dc6180200 }
            // n = 6, score = 100
            //   48898560460000       | mov                 dword ptr [ebx], eax
            //   4533f6               | dec                 eax
            //   4c89a424a0470000     | mov                 eax, ebx
            //   418bfe               | dec                 eax
            //   4c89bc24b0470000     | add                 esp, 0x20
            //   4c8d3dc6180200       | dec                 eax

        $sequence_8 = { 740b 488b4010 ffc3 4885c0 75f5 488d4e08 ff15???????? }
            // n = 7, score = 100
            //   740b                 | test                eax, eax
            //   488b4010             | inc                 ebp
            //   ffc3                 | test                eax, eax
            //   4885c0               | je                  0x331
            //   75f5                 | inc                 ecx
            //   488d4e08             | cmp                 eax, 0x2000
            //   ff15????????         |                     

        $sequence_9 = { 4889442468 c744247010000000 448bcd 4889742448 4889742440 89742438 4889742430 }
            // n = 7, score = 100
            //   4889442468           | lea                 eax, dword ptr [ebx - 0x38]
            //   c744247010000000     | mov                 dword ptr [esp + 0x50], ebx
            //   448bcd               | dec                 ebp
            //   4889742448           | mov                 dword ptr [ebx - 0x30], eax
            //   4889742440           | mov                 dword ptr [esp + 0x38], ebx
            //   89742438             | dec                 esp
            //   4889742430           | lea                 eax, dword ptr [ebp + 0x970]

    condition:
        7 of them and filesize < 643072
}