rule win_fanny_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.fanny."
        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.fanny"
        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 = { 0f84f0000000 b941000000 33c0 8bfe 6a5c f3ab 55 }
            // n = 7, score = 200
            //   0f84f0000000         | je                  0xf6
            //   b941000000           | mov                 ecx, 0x41
            //   33c0                 | xor                 eax, eax
            //   8bfe                 | mov                 edi, esi
            //   6a5c                 | push                0x5c
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax
            //   55                   | push                ebp

        $sequence_1 = { 8d45f8 50 8d45bc 6a00 50 }
            // n = 5, score = 200
            //   8d45f8               | lea                 eax, [ebp - 8]
            //   50                   | push                eax
            //   8d45bc               | lea                 eax, [ebp - 0x44]
            //   6a00                 | push                0
            //   50                   | push                eax

        $sequence_2 = { 56 e8???????? 3dfe000000 59 }
            // n = 4, score = 200
            //   56                   | push                esi
            //   e8????????           |                     
            //   3dfe000000           | cmp                 eax, 0xfe
            //   59                   | pop                 ecx

        $sequence_3 = { 3bd9 7311 2bc3 83c011 }
            // n = 4, score = 200
            //   3bd9                 | cmp                 ebx, ecx
            //   7311                 | jae                 0x13
            //   2bc3                 | sub                 eax, ebx
            //   83c011               | add                 eax, 0x11

        $sequence_4 = { 5b 59 c20c00 56 8b742410 68???????? }
            // n = 6, score = 200
            //   5b                   | pop                 ebx
            //   59                   | pop                 ecx
            //   c20c00               | ret                 0xc
            //   56                   | push                esi
            //   8b742410             | mov                 esi, dword ptr [esp + 0x10]
            //   68????????           |                     

        $sequence_5 = { 50 56 e8???????? 59 8bd8 59 eb2c }
            // n = 7, score = 200
            //   50                   | push                eax
            //   56                   | push                esi
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   8bd8                 | mov                 ebx, eax
            //   59                   | pop                 ecx
            //   eb2c                 | jmp                 0x2e

        $sequence_6 = { 3bcf 7409 03c1 40 3bc6 }
            // n = 5, score = 200
            //   3bcf                 | cmp                 ecx, edi
            //   7409                 | je                  0xb
            //   03c1                 | add                 eax, ecx
            //   40                   | inc                 eax
            //   3bc6                 | cmp                 eax, esi

        $sequence_7 = { 8b7d0c 8bf7 8b4508 3bc3 0f84b8020000 }
            // n = 5, score = 200
            //   8b7d0c               | mov                 edi, dword ptr [ebp + 0xc]
            //   8bf7                 | mov                 esi, edi
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   3bc3                 | cmp                 eax, ebx
            //   0f84b8020000         | je                  0x2be

        $sequence_8 = { ff75f8 e8???????? 59 59 84db 758b e9???????? }
            // n = 7, score = 200
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   59                   | pop                 ecx
            //   84db                 | test                bl, bl
            //   758b                 | jne                 0xffffff8d
            //   e9????????           |                     

        $sequence_9 = { 53 ff15???????? be00000200 56 ff15???????? 3bc3 59 }
            // n = 7, score = 200
            //   53                   | push                ebx
            //   ff15????????         |                     
            //   be00000200           | mov                 esi, 0x20000
            //   56                   | push                esi
            //   ff15????????         |                     
            //   3bc3                 | cmp                 eax, ebx
            //   59                   | pop                 ecx

        $sequence_10 = { 33c0 8d7da8 f3ab c745a808000000 e8???????? 8bf0 83feff }
            // n = 7, score = 200
            //   33c0                 | xor                 eax, eax
            //   8d7da8               | lea                 edi, [ebp - 0x58]
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax
            //   c745a808000000       | mov                 dword ptr [ebp - 0x58], 8
            //   e8????????           |                     
            //   8bf0                 | mov                 esi, eax
            //   83feff               | cmp                 esi, -1

        $sequence_11 = { c745bc00000000 8d4dec e8???????? 8d4dd8 e8???????? 8b45bc e9???????? }
            // n = 7, score = 200
            //   c745bc00000000       | mov                 dword ptr [ebp - 0x44], 0
            //   8d4dec               | lea                 ecx, [ebp - 0x14]
            //   e8????????           |                     
            //   8d4dd8               | lea                 ecx, [ebp - 0x28]
            //   e8????????           |                     
            //   8b45bc               | mov                 eax, dword ptr [ebp - 0x44]
            //   e9????????           |                     

        $sequence_12 = { 3b4dd0 7d26 6a00 8b55fc 52 }
            // n = 5, score = 200
            //   3b4dd0               | cmp                 ecx, dword ptr [ebp - 0x30]
            //   7d26                 | jge                 0x28
            //   6a00                 | push                0
            //   8b55fc               | mov                 edx, dword ptr [ebp - 4]
            //   52                   | push                edx

        $sequence_13 = { 8bec 83ec08 c745fc00000000 6a01 8b4508 }
            // n = 5, score = 200
            //   8bec                 | mov                 ebp, esp
            //   83ec08               | sub                 esp, 8
            //   c745fc00000000       | mov                 dword ptr [ebp - 4], 0
            //   6a01                 | push                1
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]

        $sequence_14 = { b905000000 8dbd90fbffff 8db5d0fbffff 33d2 66f3a7 751d c745fcffffffff }
            // n = 7, score = 200
            //   b905000000           | mov                 ecx, 5
            //   8dbd90fbffff         | lea                 edi, [ebp - 0x470]
            //   8db5d0fbffff         | lea                 esi, [ebp - 0x430]
            //   33d2                 | xor                 edx, edx
            //   66f3a7               | repe cmpsd          dword ptr [esi], dword ptr es:[edi]
            //   751d                 | jne                 0x1f
            //   c745fcffffffff       | mov                 dword ptr [ebp - 4], 0xffffffff

        $sequence_15 = { 5e 5d 5b 750c ff742404 e8???????? }
            // n = 6, score = 200
            //   5e                   | pop                 esi
            //   5d                   | pop                 ebp
            //   5b                   | pop                 ebx
            //   750c                 | jne                 0xe
            //   ff742404             | push                dword ptr [esp + 4]
            //   e8????????           |                     

    condition:
        7 of them and filesize < 368640
}