rule win_gearshift_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.gearshift."
        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.gearshift"
        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 = { ff15???????? 85c0 0f84a3000000 8b8db0010000 e8???????? }
            // n = 5, score = 200
            //   ff15????????         |                     
            //   85c0                 | dec                 ecx
            //   0f84a3000000         | mov                 edx, esp
            //   8b8db0010000         | dec                 eax
            //   e8????????           |                     

        $sequence_1 = { 85c0 7589 8d7801 488bcb }
            // n = 4, score = 200
            //   85c0                 | lea                 ecx, [0xffffbd15]
            //   7589                 | dec                 ebp
            //   8d7801               | add                 eax, dword ptr [ecx + ecx*8 + 0x3ce60]
            //   488bcb               | jmp                 0x125d

        $sequence_2 = { 488bd8 4885c0 7424 ff9608010000 3db7000000 7517 488bcb }
            // n = 7, score = 200
            //   488bd8               | dec                 ebp
            //   4885c0               | mov                 dword ptr [ebx], edx
            //   7424                 | dec                 eax
            //   ff9608010000         | mov                 ebx, dword ptr [esp + 8]
            //   3db7000000           | dec                 eax
            //   7517                 | mov                 edi, dword ptr [esp + 0x10]
            //   488bcb               | ret                 

        $sequence_3 = { 4c8d258e140300 488b0d???????? eb7c 4c8d2576140300 488b0d???????? eb6c e8???????? }
            // n = 7, score = 200
            //   4c8d258e140300       | lea                 ecx, [0xffffbd15]
            //   488b0d????????       |                     
            //   eb7c                 | inc                 ecx
            //   4c8d2576140300       | test                byte ptr [eax + 0x38], 0x7f
            //   488b0d????????       |                     
            //   eb6c                 | jne                 0x5d
            //   e8????????           |                     

        $sequence_4 = { 4c8be8 4885db 7510 488d0d5db00000 ff15???????? 488bd8 }
            // n = 6, score = 200
            //   4c8be8               | sar                 eax, 5
            //   4885db               | dec                 eax
            //   7510                 | lea                 edx, [0xbd60]
            //   488d0d5db00000       | dec                 eax
            //   ff15????????         |                     
            //   488bd8               | mov                 ecx, ebx

        $sequence_5 = { 4883c440 5f e9???????? 488b5c2450 488b742458 4883c440 }
            // n = 6, score = 200
            //   4883c440             | pop                 esp
            //   5f                   | ret                 
            //   e9????????           |                     
            //   488b5c2450           | dec                 eax
            //   488b742458           | mov                 dword ptr [esp + 0x40], ebx
            //   4883c440             | mov                 ebx, dword ptr [eax + ecx + 0x88]

        $sequence_6 = { 488bd8 ff15???????? 488d15d4a90000 488bcb 488905???????? ff15???????? }
            // n = 6, score = 200
            //   488bd8               | dec                 eax
            //   ff15????????         |                     
            //   488d15d4a90000       | mov                 ebx, dword ptr [esp + 8]
            //   488bcb               | dec                 eax
            //   488905????????       |                     
            //   ff15????????         |                     

        $sequence_7 = { 488bd8 ff15???????? 488d15e2bc0000 488bcb 488905???????? }
            // n = 5, score = 200
            //   488bd8               | dec                 eax
            //   ff15????????         |                     
            //   488d15e2bc0000       | and                 dword ptr [esp + 0x20], 0
            //   488bcb               | dec                 eax
            //   488905????????       |                     

        $sequence_8 = { 57 4154 4156 4157 488dac2488feffff 4881ec78020000 33c0 }
            // n = 7, score = 200
            //   57                   | jne                 0x479
            //   4154                 | dec                 eax
            //   4156                 | mov                 ecx, dword ptr [esi + 0xb8]
            //   4157                 | dec                 ecx
            //   488dac2488feffff     | cmp                 ecx, esp
            //   4881ec78020000       | je                  0x479
            //   33c0                 | dec                 esp

        $sequence_9 = { 488d05481f0300 4c3bd0 7405 e8???????? }
            // n = 4, score = 200
            //   488d05481f0300       | dec                 eax
            //   4c3bd0               | add                 ebx, ecx
            //   7405                 | dec                 eax
            //   e8????????           |                     

    condition:
        7 of them and filesize < 540672
}

rule win_gearshift_w0 {
    meta:
        author = "Bundesamt fuer Verfassungsschutz"
        source = "https://www.verfassungsschutz.de/download/anlage-2019-12-bfv-cyber-brief-2019-01.txt"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.gearshift"
        malpedia_version = "20191207"
        malpedia_sharing = "TLP:WHITE"
        malpedia_license = ""
    strings:
        $b1 = { 4C 8D 41 24 33 D2 B9 03 00 1F 00 FF 9? F8 00 00 00 48 85 C0 74 }
        $b2 = { 4C 8B 4? 08 BA 01 00 00 00 49 8B C? FF D0 85 C0 [2-6] C7 4? 1C 01 00 00 00 B8 01 00 00 00 }
        $b3 = { 8B 4B E4 8B 53 EC 41 B8 00 40 00 00 4? 0B C? FF 9? B8 00 00 00 EB }
    condition:
        (2 of ($b*))
}