rule win_buhtrap_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        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 = "20230124"
        malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686"
        malpedia_version = "20230125"
        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 = { e8???????? 8d95f4feffff 8bc8 e8???????? 8ad8 84db 0f8599000000 }
            // n = 7, score = 400
            //   e8????????           |                     
            //   8d95f4feffff         | lea                 edx, [ebp - 0x10c]
            //   8bc8                 | mov                 ecx, eax
            //   e8????????           |                     
            //   8ad8                 | mov                 bl, al
            //   84db                 | test                bl, bl
            //   0f8599000000         | jne                 0x9f

        $sequence_2 = { 89442438 85c9 7405 e8???????? 8b44240c }
            // n = 5, score = 400
            //   89442438             | mov                 dword ptr [esp + 0x38], eax
            //   85c9                 | test                ecx, ecx
            //   7405                 | je                  7
            //   e8????????           |                     
            //   8b44240c             | mov                 eax, dword ptr [esp + 0xc]

        $sequence_3 = { 57 6a0a ff35???????? ff15???????? }
            // n = 4, score = 400
            //   57                   | push                edi
            //   6a0a                 | push                0xa
            //   ff35????????         |                     
            //   ff15????????         |                     

        $sequence_4 = { 8d54241c ff7510 83c602 8d8c2468010000 ff750c 89742424 }
            // n = 6, score = 400
            //   8d54241c             | lea                 edx, [esp + 0x1c]
            //   ff7510               | push                dword ptr [ebp + 0x10]
            //   83c602               | add                 esi, 2
            //   8d8c2468010000       | lea                 ecx, [esp + 0x168]
            //   ff750c               | push                dword ptr [ebp + 0xc]
            //   89742424             | mov                 dword ptr [esp + 0x24], esi

        $sequence_5 = { ff15???????? 8b45f4 6a3a 50 c6041800 ffd6 }
            // n = 6, score = 400
            //   ff15????????         |                     
            //   8b45f4               | mov                 eax, dword ptr [ebp - 0xc]
            //   6a3a                 | push                0x3a
            //   50                   | push                eax
            //   c6041800             | mov                 byte ptr [eax + ebx], 0
            //   ffd6                 | call                esi

        $sequence_6 = { 8945e8 e8???????? 6a0d 5a b9???????? 8945ec }
            // n = 6, score = 400
            //   8945e8               | mov                 dword ptr [ebp - 0x18], eax
            //   e8????????           |                     
            //   6a0d                 | push                0xd
            //   5a                   | pop                 edx
            //   b9????????           |                     
            //   8945ec               | mov                 dword ptr [ebp - 0x14], eax

        $sequence_7 = { 56 ff75dc ffd7 6804010000 56 ff75d8 ffd3 }
            // n = 7, score = 400
            //   56                   | push                esi
            //   ff75dc               | push                dword ptr [ebp - 0x24]
            //   ffd7                 | call                edi
            //   6804010000           | push                0x104
            //   56                   | push                esi
            //   ff75d8               | push                dword ptr [ebp - 0x28]
            //   ffd3                 | call                ebx

        $sequence_8 = { 75f5 3bf3 7560 6a14 e8???????? }
            // n = 5, score = 100
            //   75f5                 | jne                 0xfffffff7
            //   3bf3                 | cmp                 esi, ebx
            //   7560                 | jne                 0x62
            //   6a14                 | push                0x14
            //   e8????????           |                     

        $sequence_9 = { 53 8d7dcc e8???????? 59 eb09 8bc3 e8???????? }
            // n = 7, score = 100
            //   53                   | push                ebx
            //   8d7dcc               | lea                 edi, [ebp - 0x34]
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   eb09                 | jmp                 0xb
            //   8bc3                 | mov                 eax, ebx
            //   e8????????           |                     

        $sequence_10 = { 33ff 8975fc 3975f8 0f8611010000 33db 43 8d45d8 }
            // n = 7, score = 100
            //   33ff                 | xor                 edi, edi
            //   8975fc               | mov                 dword ptr [ebp - 4], esi
            //   3975f8               | cmp                 dword ptr [ebp - 8], esi
            //   0f8611010000         | jbe                 0x117
            //   33db                 | xor                 ebx, ebx
            //   43                   | inc                 ebx
            //   8d45d8               | lea                 eax, [ebp - 0x28]

        $sequence_11 = { c645ff01 5f ff75f0 e8???????? ff75f8 }
            // n = 5, score = 100
            //   c645ff01             | mov                 byte ptr [ebp - 1], 1
            //   5f                   | pop                 edi
            //   ff75f0               | push                dword ptr [ebp - 0x10]
            //   e8????????           |                     
            //   ff75f8               | push                dword ptr [ebp - 8]

        $sequence_12 = { 83c302 85f6 75ec 5f 5e }
            // n = 5, score = 100
            //   83c302               | add                 ebx, 2
            //   85f6                 | test                esi, esi
            //   75ec                 | jne                 0xffffffee
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi

        $sequence_13 = { ff75f8 ffd7 85c0 7513 }
            // n = 4, score = 100
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   ffd7                 | call                edi
            //   85c0                 | test                eax, eax
            //   7513                 | jne                 0x15

        $sequence_14 = { 8d7df4 8d75f8 8bc3 e8???????? 33ff eb3e }
            // n = 6, score = 100
            //   8d7df4               | lea                 edi, [ebp - 0xc]
            //   8d75f8               | lea                 esi, [ebp - 8]
            //   8bc3                 | mov                 eax, ebx
            //   e8????????           |                     
            //   33ff                 | xor                 edi, edi
            //   eb3e                 | jmp                 0x40

    condition:
        7 of them and filesize < 131072
}