rule win_buhtrap_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.buhtrap."
        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.buhtrap"
        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 = { e8???????? 59 59 84c0 0f8435010000 }
            // n = 5, score = 500
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   59                   | pop                 ecx
            //   84c0                 | test                al, al
            //   0f8435010000         | je                  0x13b

        $sequence_1 = { 890d???????? 66837ddc09 a2???????? 0f9405???????? e8???????? 83ec0c a2???????? }
            // n = 7, score = 400
            //   890d????????         |                     
            //   66837ddc09           | cmp                 word ptr [ebp - 0x24], 9
            //   a2????????           |                     
            //   0f9405????????       |                     
            //   e8????????           |                     
            //   83ec0c               | sub                 esp, 0xc
            //   a2????????           |                     

        $sequence_2 = { 897df4 ff15???????? 59 8bf0 }
            // n = 4, score = 400
            //   897df4               | mov                 dword ptr [ebp - 0xc], edi
            //   ff15????????         |                     
            //   59                   | pop                 ecx
            //   8bf0                 | mov                 esi, eax

        $sequence_3 = { ffb4bc48010000 8d442448 50 ff15???????? 85c0 7417 47 }
            // n = 7, score = 400
            //   ffb4bc48010000       | push                dword ptr [esp + edi*4 + 0x148]
            //   8d442448             | lea                 eax, [esp + 0x48]
            //   50                   | push                eax
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7417                 | je                  0x19
            //   47                   | inc                 edi

        $sequence_4 = { 8945c4 e8???????? 6a0b 5a b9???????? 8945f0 e8???????? }
            // n = 7, score = 400
            //   8945c4               | mov                 dword ptr [ebp - 0x3c], eax
            //   e8????????           |                     
            //   6a0b                 | push                0xb
            //   5a                   | pop                 edx
            //   b9????????           |                     
            //   8945f0               | mov                 dword ptr [ebp - 0x10], eax
            //   e8????????           |                     

        $sequence_5 = { 8bfc 8bc8 a5 a5 a5 e8???????? 83c40c }
            // n = 7, score = 400
            //   8bfc                 | mov                 edi, esp
            //   8bc8                 | mov                 ecx, eax
            //   a5                   | movsd               dword ptr es:[edi], dword ptr [esi]
            //   a5                   | movsd               dword ptr es:[edi], dword ptr [esi]
            //   a5                   | movsd               dword ptr es:[edi], dword ptr [esi]
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc

        $sequence_6 = { 57 ffd6 6a0e 5a }
            // n = 4, score = 400
            //   57                   | push                edi
            //   ffd6                 | call                esi
            //   6a0e                 | push                0xe
            //   5a                   | pop                 edx

        $sequence_7 = { ffd3 59 59 5f 5e }
            // n = 5, score = 400
            //   ffd3                 | call                ebx
            //   59                   | pop                 ecx
            //   59                   | pop                 ecx
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi

        $sequence_8 = { e8???????? 837e3004 c745fc00f74084 7507 c745fc00f7c084 f6450c01 }
            // n = 6, score = 100
            //   e8????????           |                     
            //   837e3004             | cmp                 dword ptr [esi + 0x30], 4
            //   c745fc00f74084       | mov                 dword ptr [ebp - 4], 0x8440f700
            //   7507                 | jne                 9
            //   c745fc00f7c084       | mov                 dword ptr [ebp - 4], 0x84c0f700
            //   f6450c01             | test                byte ptr [ebp + 0xc], 1

        $sequence_9 = { 8d3441 66833e00 7529 85c0 750c }
            // n = 5, score = 100
            //   8d3441               | lea                 esi, [ecx + eax*2]
            //   66833e00             | cmp                 word ptr [esi], 0
            //   7529                 | jne                 0x2b
            //   85c0                 | test                eax, eax
            //   750c                 | jne                 0xe

        $sequence_10 = { ff7624 ff15???????? 8bd8 85db 0f84c4000000 6a68 }
            // n = 6, score = 100
            //   ff7624               | push                dword ptr [esi + 0x24]
            //   ff15????????         |                     
            //   8bd8                 | mov                 ebx, eax
            //   85db                 | test                ebx, ebx
            //   0f84c4000000         | je                  0xca
            //   6a68                 | push                0x68

        $sequence_11 = { 83c414 56 68d69abbe7 6a05 68???????? 8945b8 }
            // n = 6, score = 100
            //   83c414               | add                 esp, 0x14
            //   56                   | push                esi
            //   68d69abbe7           | push                0xe7bb9ad6
            //   6a05                 | push                5
            //   68????????           |                     
            //   8945b8               | mov                 dword ptr [ebp - 0x48], eax

        $sequence_12 = { ff74245c 894610 ffd5 894614 8b4710 }
            // n = 5, score = 100
            //   ff74245c             | push                dword ptr [esp + 0x5c]
            //   894610               | mov                 dword ptr [esi + 0x10], eax
            //   ffd5                 | call                ebp
            //   894614               | mov                 dword ptr [esi + 0x14], eax
            //   8b4710               | mov                 eax, dword ptr [edi + 0x10]

        $sequence_13 = { ff7610 57 e8???????? 8b7614 }
            // n = 4, score = 100
            //   ff7610               | push                dword ptr [esi + 0x10]
            //   57                   | push                edi
            //   e8????????           |                     
            //   8b7614               | mov                 esi, dword ptr [esi + 0x14]

        $sequence_14 = { eb60 8365e400 8365fc00 85db }
            // n = 4, score = 100
            //   eb60                 | jmp                 0x62
            //   8365e400             | and                 dword ptr [ebp - 0x1c], 0
            //   8365fc00             | and                 dword ptr [ebp - 4], 0
            //   85db                 | test                ebx, ebx

    condition:
        7 of them and filesize < 131072
}