rule win_gcman_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.gcman."
        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.gcman"
        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 = { 01f0 052211906b c1c007 01d0 89d6 31ce 21c6 }
            // n = 7, score = 100
            //   01f0                 | add                 eax, esi
            //   052211906b           | add                 eax, 0x6b901122
            //   c1c007               | rol                 eax, 7
            //   01d0                 | add                 eax, edx
            //   89d6                 | mov                 esi, edx
            //   31ce                 | xor                 esi, ecx
            //   21c6                 | and                 esi, eax

        $sequence_1 = { 80385c 740a 8b45f4 80382f 7402 eb07 }
            // n = 6, score = 100
            //   80385c               | cmp                 byte ptr [eax], 0x5c
            //   740a                 | je                  0xc
            //   8b45f4               | mov                 eax, dword ptr [ebp - 0xc]
            //   80382f               | cmp                 byte ptr [eax], 0x2f
            //   7402                 | je                  4
            //   eb07                 | jmp                 9

        $sequence_2 = { e8???????? a3???????? 8b45f8 890424 e8???????? }
            // n = 5, score = 100
            //   e8????????           |                     
            //   a3????????           |                     
            //   8b45f8               | mov                 eax, dword ptr [ebp - 8]
            //   890424               | mov                 dword ptr [esp], eax
            //   e8????????           |                     

        $sequence_3 = { c1e808 8802 8b5508 83c202 8b450c 8b00 }
            // n = 6, score = 100
            //   c1e808               | shr                 eax, 8
            //   8802                 | mov                 byte ptr [edx], al
            //   8b5508               | mov                 edx, dword ptr [ebp + 8]
            //   83c202               | add                 edx, 2
            //   8b450c               | mov                 eax, dword ptr [ebp + 0xc]
            //   8b00                 | mov                 eax, dword ptr [eax]

        $sequence_4 = { 803800 7434 8b4508 80385c }
            // n = 4, score = 100
            //   803800               | cmp                 byte ptr [eax], 0
            //   7434                 | je                  0x36
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   80385c               | cmp                 byte ptr [eax], 0x5c

        $sequence_5 = { 0375c4 01f2 81eaff6ab902 c1c216 01ca 89ce 31de }
            // n = 7, score = 100
            //   0375c4               | add                 esi, dword ptr [ebp - 0x3c]
            //   01f2                 | add                 edx, esi
            //   81eaff6ab902         | sub                 edx, 0x2b96aff
            //   c1c216               | rol                 edx, 0x16
            //   01ca                 | add                 edx, ecx
            //   89ce                 | mov                 esi, ecx
            //   31de                 | xor                 esi, ebx

        $sequence_6 = { 83c208 8b4508 83c008 8b00 01c8 8902 8b5508 }
            // n = 7, score = 100
            //   83c208               | add                 edx, 8
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   83c008               | add                 eax, 8
            //   8b00                 | mov                 eax, dword ptr [eax]
            //   01c8                 | add                 eax, ecx
            //   8902                 | mov                 dword ptr [edx], eax
            //   8b5508               | mov                 edx, dword ptr [ebp + 8]

        $sequence_7 = { 83ec10 85c0 750f c78554efffff00000000 }
            // n = 4, score = 100
            //   83ec10               | sub                 esp, 0x10
            //   85c0                 | test                eax, eax
            //   750f                 | jne                 0x11
            //   c78554efffff00000000     | mov    dword ptr [ebp - 0x10ac], 0

        $sequence_8 = { c705????????01000000 c745c400000000 e9???????? 8b45d4 a3???????? c7042400040000 e8???????? }
            // n = 7, score = 100
            //   c705????????01000000     |     
            //   c745c400000000       | mov                 dword ptr [ebp - 0x3c], 0
            //   e9????????           |                     
            //   8b45d4               | mov                 eax, dword ptr [ebp - 0x2c]
            //   a3????????           |                     
            //   c7042400040000       | mov                 dword ptr [esp], 0x400
            //   e8????????           |                     

        $sequence_9 = { 81e9830b1000 c1c10f 01d9 89c6 f7d6 }
            // n = 5, score = 100
            //   81e9830b1000         | sub                 ecx, 0x100b83
            //   c1c10f               | rol                 ecx, 0xf
            //   01d9                 | add                 ecx, ebx
            //   89c6                 | mov                 esi, eax
            //   f7d6                 | not                 esi

    condition:
        7 of them and filesize < 81920
}