rule win_chairsmack_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.chairsmack."
        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.chairsmack"
        malpedia_rule_date = "20260916"
        malpedia_hash = "53a643781c18e08f4a50949af60172d837a0b6f6"
        malpedia_version = "20260917"
        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 = { 8d4db8 6a06 68???????? e8???????? 6aff 6a00 68???????? }
            // n = 7, score = 200
            //   8d4db8               | lea                 ecx, [ebp - 0x48]
            //   6a06                 | push                6
            //   68????????           |                     
            //   e8????????           |                     
            //   6aff                 | push                -1
            //   6a00                 | push                0
            //   68????????           |                     

        $sequence_1 = { 0f8534010000 8b5508 8b0495cc504a00 83e001 743e 8b4d08 833c8dd8504a00ff }
            // n = 7, score = 200
            //   0f8534010000         | jne                 0x13a
            //   8b5508               | mov                 edx, dword ptr [ebp + 8]
            //   8b0495cc504a00       | mov                 eax, dword ptr [edx*4 + 0x4a50cc]
            //   83e001               | and                 eax, 1
            //   743e                 | je                  0x40
            //   8b4d08               | mov                 ecx, dword ptr [ebp + 8]
            //   833c8dd8504a00ff     | cmp                 dword ptr [ecx*4 + 0x4a50d8], -1

        $sequence_2 = { 8b55fc 52 ff15???????? 3305???????? b904000000 6bd105 8982a0784a00 }
            // n = 7, score = 200
            //   8b55fc               | mov                 edx, dword ptr [ebp - 4]
            //   52                   | push                edx
            //   ff15????????         |                     
            //   3305????????         |                     
            //   b904000000           | mov                 ecx, 4
            //   6bd105               | imul                edx, ecx, 5
            //   8982a0784a00         | mov                 dword ptr [edx + 0x4a78a0], eax

        $sequence_3 = { 8d84240c010000 8bcc 8964242c 50 e8???????? 83ec1c c68424b803000084 }
            // n = 7, score = 200
            //   8d84240c010000       | lea                 eax, [esp + 0x10c]
            //   8bcc                 | mov                 ecx, esp
            //   8964242c             | mov                 dword ptr [esp + 0x2c], esp
            //   50                   | push                eax
            //   e8????????           |                     
            //   83ec1c               | sub                 esp, 0x1c
            //   c68424b803000084     | mov                 byte ptr [esp + 0x3b8], 0x84

        $sequence_4 = { 894608 83ec0c c645fc03 8bf4 c70600000000 }
            // n = 5, score = 200
            //   894608               | mov                 dword ptr [esi + 8], eax
            //   83ec0c               | sub                 esp, 0xc
            //   c645fc03             | mov                 byte ptr [ebp - 4], 3
            //   8bf4                 | mov                 esi, esp
            //   c70600000000         | mov                 dword ptr [esi], 0

        $sequence_5 = { 8b0495e89b4800 0fb74df8 8b55f4 0fb70442 33c1 0fbf4dfc 8b148de89b4800 }
            // n = 7, score = 200
            //   8b0495e89b4800       | mov                 eax, dword ptr [edx*4 + 0x489be8]
            //   0fb74df8             | movzx               ecx, word ptr [ebp - 8]
            //   8b55f4               | mov                 edx, dword ptr [ebp - 0xc]
            //   0fb70442             | movzx               eax, word ptr [edx + eax*2]
            //   33c1                 | xor                 eax, ecx
            //   0fbf4dfc             | movsx               ecx, word ptr [ebp - 4]
            //   8b148de89b4800       | mov                 edx, dword ptr [ecx*4 + 0x489be8]

        $sequence_6 = { 8964242c 68???????? e8???????? 83ec1c c68424b803000055 8bcc 8964244c }
            // n = 7, score = 200
            //   8964242c             | mov                 dword ptr [esp + 0x2c], esp
            //   68????????           |                     
            //   e8????????           |                     
            //   83ec1c               | sub                 esp, 0x1c
            //   c68424b803000055     | mov                 byte ptr [esp + 0x3b8], 0x55
            //   8bcc                 | mov                 ecx, esp
            //   8964244c             | mov                 dword ptr [esp + 0x4c], esp

        $sequence_7 = { 0f840f000000 8365f0fe 8b4de0 83c170 e9???????? c3 8d4dec }
            // n = 7, score = 200
            //   0f840f000000         | je                  0x15
            //   8365f0fe             | and                 dword ptr [ebp - 0x10], 0xfffffffe
            //   8b4de0               | mov                 ecx, dword ptr [ebp - 0x20]
            //   83c170               | add                 ecx, 0x70
            //   e9????????           |                     
            //   c3                   | ret                 
            //   8d4dec               | lea                 ecx, [ebp - 0x14]

        $sequence_8 = { 6a19 68???????? 8d4c2450 c68424880300001c e8???????? 837c246010 8d74244c }
            // n = 7, score = 200
            //   6a19                 | push                0x19
            //   68????????           |                     
            //   8d4c2450             | lea                 ecx, [esp + 0x50]
            //   c68424880300001c     | mov                 byte ptr [esp + 0x388], 0x1c
            //   e8????????           |                     
            //   837c246010           | cmp                 dword ptr [esp + 0x60], 0x10
            //   8d74244c             | lea                 esi, [esp + 0x4c]

        $sequence_9 = { e8???????? 6aff 6a00 8d842488000000 c684248803000081 50 8d4c2454 }
            // n = 7, score = 200
            //   e8????????           |                     
            //   6aff                 | push                -1
            //   6a00                 | push                0
            //   8d842488000000       | lea                 eax, [esp + 0x88]
            //   c684248803000081     | mov                 byte ptr [esp + 0x388], 0x81
            //   50                   | push                eax
            //   8d4c2454             | lea                 ecx, [esp + 0x54]

    condition:
        7 of them and filesize < 1974272
}