rule win_cohhoc_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.cohhoc."
        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.cohhoc"
        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 = { c1e204 8d4c0c10 43 8a1411 }
            // n = 4, score = 300
            //   c1e204               | shl                 edx, 4
            //   8d4c0c10             | lea                 ecx, [esp + ecx + 0x10]
            //   43                   | inc                 ebx
            //   8a1411               | mov                 dl, byte ptr [ecx + edx]

        $sequence_1 = { 8d542450 f3ab 8dbc24b4010000 83c9ff f2ae f7d1 2bf9 }
            // n = 7, score = 300
            //   8d542450             | lea                 edx, [esp + 0x50]
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax
            //   8dbc24b4010000       | lea                 edi, [esp + 0x1b4]
            //   83c9ff               | or                  ecx, 0xffffffff
            //   f2ae                 | repne scasb         al, byte ptr es:[edi]
            //   f7d1                 | not                 ecx
            //   2bf9                 | sub                 edi, ecx

        $sequence_2 = { 7509 c7451800000000 eb05 03f0 8975f4 8b4de0 85c9 }
            // n = 7, score = 300
            //   7509                 | jne                 0xb
            //   c7451800000000       | mov                 dword ptr [ebp + 0x18], 0
            //   eb05                 | jmp                 7
            //   03f0                 | add                 esi, eax
            //   8975f4               | mov                 dword ptr [ebp - 0xc], esi
            //   8b4de0               | mov                 ecx, dword ptr [ebp - 0x20]
            //   85c9                 | test                ecx, ecx

        $sequence_3 = { 33d2 f3ab 8915???????? 68???????? 8915???????? 8915???????? 8915???????? }
            // n = 7, score = 300
            //   33d2                 | xor                 edx, edx
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax
            //   8915????????         |                     
            //   68????????           |                     
            //   8915????????         |                     
            //   8915????????         |                     
            //   8915????????         |                     

        $sequence_4 = { 53 ffd6 b911000000 33c0 8d7c2424 33d2 f3ab }
            // n = 7, score = 300
            //   53                   | push                ebx
            //   ffd6                 | call                esi
            //   b911000000           | mov                 ecx, 0x11
            //   33c0                 | xor                 eax, eax
            //   8d7c2424             | lea                 edi, [esp + 0x24]
            //   33d2                 | xor                 edx, edx
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax

        $sequence_5 = { 8b7c240c 33c9 85ff 7622 56 }
            // n = 5, score = 300
            //   8b7c240c             | mov                 edi, dword ptr [esp + 0xc]
            //   33c9                 | xor                 ecx, ecx
            //   85ff                 | test                edi, edi
            //   7622                 | jbe                 0x24
            //   56                   | push                esi

        $sequence_6 = { 5b 81c4bc030000 c20c00 8b8424d4030000 8d942488010000 52 }
            // n = 6, score = 300
            //   5b                   | pop                 ebx
            //   81c4bc030000         | add                 esp, 0x3bc
            //   c20c00               | ret                 0xc
            //   8b8424d4030000       | mov                 eax, dword ptr [esp + 0x3d4]
            //   8d942488010000       | lea                 edx, [esp + 0x188]
            //   52                   | push                edx

        $sequence_7 = { 8be8 3bee 751b 8b4c2410 56 51 }
            // n = 6, score = 300
            //   8be8                 | mov                 ebp, eax
            //   3bee                 | cmp                 ebp, esi
            //   751b                 | jne                 0x1d
            //   8b4c2410             | mov                 ecx, dword ptr [esp + 0x10]
            //   56                   | push                esi
            //   51                   | push                ecx

        $sequence_8 = { 89410c 8b4c2410 8b442414 41 48 894c2410 89442414 }
            // n = 7, score = 300
            //   89410c               | mov                 dword ptr [ecx + 0xc], eax
            //   8b4c2410             | mov                 ecx, dword ptr [esp + 0x10]
            //   8b442414             | mov                 eax, dword ptr [esp + 0x14]
            //   41                   | inc                 ecx
            //   48                   | dec                 eax
            //   894c2410             | mov                 dword ptr [esp + 0x10], ecx
            //   89442414             | mov                 dword ptr [esp + 0x14], eax

        $sequence_9 = { 8b44243a 25ffff0000 0faf442430 83c01f 24e0 99 83e207 }
            // n = 7, score = 300
            //   8b44243a             | mov                 eax, dword ptr [esp + 0x3a]
            //   25ffff0000           | and                 eax, 0xffff
            //   0faf442430           | imul                eax, dword ptr [esp + 0x30]
            //   83c01f               | add                 eax, 0x1f
            //   24e0                 | and                 al, 0xe0
            //   99                   | cdq                 
            //   83e207               | and                 edx, 7

    condition:
        7 of them and filesize < 253952
}