rule win_bitsloth_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.bitsloth."
        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.bitsloth"
        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???????? 83c404 0fb6c0 85c0 7417 8b8d4cf1ffff 51 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   0fb6c0               | movzx               eax, al
            //   85c0                 | test                eax, eax
            //   7417                 | je                  0x19
            //   8b8d4cf1ffff         | mov                 ecx, dword ptr [ebp - 0xeb4]
            //   51                   | push                ecx

        $sequence_1 = { 898ddcfeffff 898de0feffff 898de4feffff 898de8feffff 8d958cfeffff 52 ff15???????? }
            // n = 7, score = 100
            //   898ddcfeffff         | mov                 dword ptr [ebp - 0x124], ecx
            //   898de0feffff         | mov                 dword ptr [ebp - 0x120], ecx
            //   898de4feffff         | mov                 dword ptr [ebp - 0x11c], ecx
            //   898de8feffff         | mov                 dword ptr [ebp - 0x118], ecx
            //   8d958cfeffff         | lea                 edx, [ebp - 0x174]
            //   52                   | push                edx
            //   ff15????????         |                     

        $sequence_2 = { 8b8d9cfdffff 51 ff15???????? 6800800000 6a00 8b95a0fdffff 52 }
            // n = 7, score = 100
            //   8b8d9cfdffff         | mov                 ecx, dword ptr [ebp - 0x264]
            //   51                   | push                ecx
            //   ff15????????         |                     
            //   6800800000           | push                0x8000
            //   6a00                 | push                0
            //   8b95a0fdffff         | mov                 edx, dword ptr [ebp - 0x260]
            //   52                   | push                edx

        $sequence_3 = { 6a00 68224e0000 e8???????? 83c40c 0fb60d???????? 83f901 7520 }
            // n = 7, score = 100
            //   6a00                 | push                0
            //   68224e0000           | push                0x4e22
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   0fb60d????????       |                     
            //   83f901               | cmp                 ecx, 1
            //   7520                 | jne                 0x22

        $sequence_4 = { 8985dcdbffff 83bddcdbffff00 752c 68???????? e8???????? 83c404 8b550c }
            // n = 7, score = 100
            //   8985dcdbffff         | mov                 dword ptr [ebp - 0x2424], eax
            //   83bddcdbffff00       | cmp                 dword ptr [ebp - 0x2424], 0
            //   752c                 | jne                 0x2e
            //   68????????           |                     
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   8b550c               | mov                 edx, dword ptr [ebp + 0xc]

        $sequence_5 = { 8b4584 50 ff15???????? 85c0 7432 68???????? 8b0d???????? }
            // n = 7, score = 100
            //   8b4584               | mov                 eax, dword ptr [ebp - 0x7c]
            //   50                   | push                eax
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7432                 | je                  0x34
            //   68????????           |                     
            //   8b0d????????         |                     

        $sequence_6 = { 837d0c64 7512 68???????? 8d4dd8 e8???????? e9???????? 837d0c65 }
            // n = 7, score = 100
            //   837d0c64             | cmp                 dword ptr [ebp + 0xc], 0x64
            //   7512                 | jne                 0x14
            //   68????????           |                     
            //   8d4dd8               | lea                 ecx, [ebp - 0x28]
            //   e8????????           |                     
            //   e9????????           |                     
            //   837d0c65             | cmp                 dword ptr [ebp + 0xc], 0x65

        $sequence_7 = { c3 8b04c514fe0310 5d c3 55 8bec 81ecfc010000 }
            // n = 7, score = 100
            //   c3                   | ret                 
            //   8b04c514fe0310       | mov                 eax, dword ptr [eax*8 + 0x1003fe14]
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   81ecfc010000         | sub                 esp, 0x1fc

        $sequence_8 = { 80e17f 884c3704 eb13 80c980 884c3704 8b049d88d00410 8064302480 }
            // n = 7, score = 100
            //   80e17f               | and                 cl, 0x7f
            //   884c3704             | mov                 byte ptr [edi + esi + 4], cl
            //   eb13                 | jmp                 0x15
            //   80c980               | or                  cl, 0x80
            //   884c3704             | mov                 byte ptr [edi + esi + 4], cl
            //   8b049d88d00410       | mov                 eax, dword ptr [ebx*4 + 0x1004d088]
            //   8064302480           | and                 byte ptr [eax + esi + 0x24], 0x80

        $sequence_9 = { c645fc02 8b4df0 8b11 8b4204 8b4df0 c70401???????? }
            // n = 6, score = 100
            //   c645fc02             | mov                 byte ptr [ebp - 4], 2
            //   8b4df0               | mov                 ecx, dword ptr [ebp - 0x10]
            //   8b11                 | mov                 edx, dword ptr [ecx]
            //   8b4204               | mov                 eax, dword ptr [edx + 4]
            //   8b4df0               | mov                 ecx, dword ptr [ebp - 0x10]
            //   c70401????????       |                     

    condition:
        7 of them and filesize < 677888
}