rule win_biscuit_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.biscuit."
        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.biscuit"
        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 = { 7511 8b9594feffff 2b55e4 899588feffff eb10 e9???????? }
            // n = 6, score = 100
            //   7511                 | jne                 0x13
            //   8b9594feffff         | mov                 edx, dword ptr [ebp - 0x16c]
            //   2b55e4               | sub                 edx, dword ptr [ebp - 0x1c]
            //   899588feffff         | mov                 dword ptr [ebp - 0x178], edx
            //   eb10                 | jmp                 0x12
            //   e9????????           |                     

        $sequence_1 = { 83c404 eb1f 8b55e4 83ea01 899530feffff }
            // n = 5, score = 100
            //   83c404               | add                 esp, 4
            //   eb1f                 | jmp                 0x21
            //   8b55e4               | mov                 edx, dword ptr [ebp - 0x1c]
            //   83ea01               | sub                 edx, 1
            //   899530feffff         | mov                 dword ptr [ebp - 0x1d0], edx

        $sequence_2 = { 33c0 f2ae f7d1 83c1ff 898d889fffff 83bd889fffff00 751f }
            // n = 7, score = 100
            //   33c0                 | xor                 eax, eax
            //   f2ae                 | repne scasb         al, byte ptr es:[edi]
            //   f7d1                 | not                 ecx
            //   83c1ff               | add                 ecx, -1
            //   898d889fffff         | mov                 dword ptr [ebp - 0x6078], ecx
            //   83bd889fffff00       | cmp                 dword ptr [ebp - 0x6078], 0
            //   751f                 | jne                 0x21

        $sequence_3 = { 85c0 7412 0fbe85f0dfffff 83e820 8885d09fffff eb0c 8a8df0dfffff }
            // n = 7, score = 100
            //   85c0                 | test                eax, eax
            //   7412                 | je                  0x14
            //   0fbe85f0dfffff       | movsx               eax, byte ptr [ebp - 0x2010]
            //   83e820               | sub                 eax, 0x20
            //   8885d09fffff         | mov                 byte ptr [ebp - 0x6030], al
            //   eb0c                 | jmp                 0xe
            //   8a8df0dfffff         | mov                 cl, byte ptr [ebp - 0x2010]

        $sequence_4 = { 8b95d8feffff 52 e8???????? 83c404 eb22 8b8558ffffff 83e801 }
            // n = 7, score = 100
            //   8b95d8feffff         | mov                 edx, dword ptr [ebp - 0x128]
            //   52                   | push                edx
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   eb22                 | jmp                 0x24
            //   8b8558ffffff         | mov                 eax, dword ptr [ebp - 0xa8]
            //   83e801               | sub                 eax, 1

        $sequence_5 = { 8a4c040c 40 f6d1 884c040b 3bc6 7cf1 }
            // n = 6, score = 100
            //   8a4c040c             | mov                 cl, byte ptr [esp + eax + 0xc]
            //   40                   | inc                 eax
            //   f6d1                 | not                 cl
            //   884c040b             | mov                 byte ptr [esp + eax + 0xb], cl
            //   3bc6                 | cmp                 eax, esi
            //   7cf1                 | jl                  0xfffffff3

        $sequence_6 = { 83c1ff 51 6a00 68???????? 8d4dd8 e8???????? 8985d4b7ffff }
            // n = 7, score = 100
            //   83c1ff               | add                 ecx, -1
            //   51                   | push                ecx
            //   6a00                 | push                0
            //   68????????           |                     
            //   8d4dd8               | lea                 ecx, [ebp - 0x28]
            //   e8????????           |                     
            //   8985d4b7ffff         | mov                 dword ptr [ebp - 0x482c], eax

        $sequence_7 = { 52 e8???????? 83c404 eb22 8b85e8faffff }
            // n = 5, score = 100
            //   52                   | push                edx
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   eb22                 | jmp                 0x24
            //   8b85e8faffff         | mov                 eax, dword ptr [ebp - 0x518]

        $sequence_8 = { 895e48 895e4c 8b4620 3bc3 741d 8d48ff }
            // n = 6, score = 100
            //   895e48               | mov                 dword ptr [esi + 0x48], ebx
            //   895e4c               | mov                 dword ptr [esi + 0x4c], ebx
            //   8b4620               | mov                 eax, dword ptr [esi + 0x20]
            //   3bc3                 | cmp                 eax, ebx
            //   741d                 | je                  0x1f
            //   8d48ff               | lea                 ecx, [eax - 1]

        $sequence_9 = { 0f856a050000 b980000000 33c0 8dbd40fdffff }
            // n = 4, score = 100
            //   0f856a050000         | jne                 0x570
            //   b980000000           | mov                 ecx, 0x80
            //   33c0                 | xor                 eax, eax
            //   8dbd40fdffff         | lea                 edi, [ebp - 0x2c0]

    condition:
        7 of them and filesize < 180224
}