rule win_biscuit_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        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 = "20260422"
        malpedia_hash = "a182e35da64e6d71cb55f125c4d4225196523f14"
        malpedia_version = "20260504"
        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 = { 8810 c78550b9ffff00000000 c78554b9ffff00000000 c78558b9ffff00000000 8d8d5cb9ffff e8???????? }
            // n = 6, score = 100
            //   8810                 | mov                 byte ptr [eax], dl
            //   c78550b9ffff00000000     | mov    dword ptr [ebp - 0x46b0], 0
            //   c78554b9ffff00000000     | mov    dword ptr [ebp - 0x46ac], 0
            //   c78558b9ffff00000000     | mov    dword ptr [ebp - 0x46a8], 0
            //   8d8d5cb9ffff         | lea                 ecx, [ebp - 0x46a4]
            //   e8????????           |                     

        $sequence_1 = { ff2485d07f4000 c7442410e8b84000 eb1c c7442410e4b84000 eb12 c7442410dcb84000 eb08 }
            // n = 7, score = 100
            //   ff2485d07f4000       | jmp                 dword ptr [eax*4 + 0x407fd0]
            //   c7442410e8b84000     | mov                 dword ptr [esp + 0x10], 0x40b8e8
            //   eb1c                 | jmp                 0x1e
            //   c7442410e4b84000     | mov                 dword ptr [esp + 0x10], 0x40b8e4
            //   eb12                 | jmp                 0x14
            //   c7442410dcb84000     | mov                 dword ptr [esp + 0x10], 0x40b8dc
            //   eb08                 | jmp                 0xa

        $sequence_2 = { 83c002 8985f8b6ffff 8b8de8faffff 83e901 898dfcb6ffff 8b95fcb6ffff }
            // n = 6, score = 100
            //   83c002               | add                 eax, 2
            //   8985f8b6ffff         | mov                 dword ptr [ebp - 0x4908], eax
            //   8b8de8faffff         | mov                 ecx, dword ptr [ebp - 0x518]
            //   83e901               | sub                 ecx, 1
            //   898dfcb6ffff         | mov                 dword ptr [ebp - 0x4904], ecx
            //   8b95fcb6ffff         | mov                 edx, dword ptr [ebp - 0x4904]

        $sequence_3 = { 51 52 8d45f4 6aff 50 6a65 }
            // n = 6, score = 100
            //   51                   | push                ecx
            //   52                   | push                edx
            //   8d45f4               | lea                 eax, [ebp - 0xc]
            //   6aff                 | push                -1
            //   50                   | push                eax
            //   6a65                 | push                0x65

        $sequence_4 = { 752f 8b8d58b8ffff 83c102 898de0b6ffff 8b9550b8ffff 83ea01 8995e4b6ffff }
            // n = 7, score = 100
            //   752f                 | jne                 0x31
            //   8b8d58b8ffff         | mov                 ecx, dword ptr [ebp - 0x47a8]
            //   83c102               | add                 ecx, 2
            //   898de0b6ffff         | mov                 dword ptr [ebp - 0x4920], ecx
            //   8b9550b8ffff         | mov                 edx, dword ptr [ebp - 0x47b0]
            //   83ea01               | sub                 edx, 1
            //   8995e4b6ffff         | mov                 dword ptr [ebp - 0x491c], edx

        $sequence_5 = { 33d2 8a51ff 81faff000000 752f 8b8580fbffff 83c002 8985f0b6ffff }
            // n = 7, score = 100
            //   33d2                 | xor                 edx, edx
            //   8a51ff               | mov                 dl, byte ptr [ecx - 1]
            //   81faff000000         | cmp                 edx, 0xff
            //   752f                 | jne                 0x31
            //   8b8580fbffff         | mov                 eax, dword ptr [ebp - 0x480]
            //   83c002               | add                 eax, 2
            //   8985f0b6ffff         | mov                 dword ptr [ebp - 0x4910], eax

        $sequence_6 = { 81c440220000 c20c00 b900080000 33c0 8dbc2450020000 53 f3ab }
            // n = 7, score = 100
            //   81c440220000         | add                 esp, 0x2240
            //   c20c00               | ret                 0xc
            //   b900080000           | mov                 ecx, 0x800
            //   33c0                 | xor                 eax, eax
            //   8dbc2450020000       | lea                 edi, [esp + 0x250]
            //   53                   | push                ebx
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax

        $sequence_7 = { 83bd08ffffff00 7573 c645bc00 33d2 8955a8 }
            // n = 5, score = 100
            //   83bd08ffffff00       | cmp                 dword ptr [ebp - 0xf8], 0
            //   7573                 | jne                 0x75
            //   c645bc00             | mov                 byte ptr [ebp - 0x44], 0
            //   33d2                 | xor                 edx, edx
            //   8955a8               | mov                 dword ptr [ebp - 0x58], edx

        $sequence_8 = { 898d00ffffff 8b55e4 0395ecfeffff 8995f8feffff }
            // n = 4, score = 100
            //   898d00ffffff         | mov                 dword ptr [ebp - 0x100], ecx
            //   8b55e4               | mov                 edx, dword ptr [ebp - 0x1c]
            //   0395ecfeffff         | add                 edx, dword ptr [ebp - 0x114]
            //   8995f8feffff         | mov                 dword ptr [ebp - 0x108], edx

        $sequence_9 = { 895e5c 8b4644 3bc3 741d 8d48ff 8a40ff 3ac3 }
            // n = 7, score = 100
            //   895e5c               | mov                 dword ptr [esi + 0x5c], ebx
            //   8b4644               | mov                 eax, dword ptr [esi + 0x44]
            //   3bc3                 | cmp                 eax, ebx
            //   741d                 | je                  0x1f
            //   8d48ff               | lea                 ecx, [eax - 1]
            //   8a40ff               | mov                 al, byte ptr [eax - 1]
            //   3ac3                 | cmp                 al, bl

    condition:
        7 of them and filesize < 180224
}