rule win_fanny_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        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 = "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 = { 8d4508 50 683f000f00 8d458c }
            // n = 4, score = 200
            //   8d4508               | lea                 eax, [ebp + 8]
            //   50                   | push                eax
            //   683f000f00           | push                0xf003f
            //   8d458c               | lea                 eax, [ebp - 0x74]

        $sequence_1 = { 750e 8b55c8 0fb64201 83f825 7502 }
            // n = 5, score = 200
            //   750e                 | jne                 0x10
            //   8b55c8               | mov                 edx, dword ptr [ebp - 0x38]
            //   0fb64201             | movzx               eax, byte ptr [edx + 1]
            //   83f825               | cmp                 eax, 0x25
            //   7502                 | jne                 4

        $sequence_2 = { aa 885c241b 895c2430 895c2444 c744243c02000000 8974242c }
            // n = 6, score = 200
            //   aa                   | stosb               byte ptr es:[edi], al
            //   885c241b             | mov                 byte ptr [esp + 0x1b], bl
            //   895c2430             | mov                 dword ptr [esp + 0x30], ebx
            //   895c2444             | mov                 dword ptr [esp + 0x44], ebx
            //   c744243c02000000     | mov                 dword ptr [esp + 0x3c], 2
            //   8974242c             | mov                 dword ptr [esp + 0x2c], esi

        $sequence_3 = { 85f6 7438 ff7604 ff15???????? 8bd8 }
            // n = 5, score = 200
            //   85f6                 | test                esi, esi
            //   7438                 | je                  0x3a
            //   ff7604               | push                dword ptr [esi + 4]
            //   ff15????????         |                     
            //   8bd8                 | mov                 ebx, eax

        $sequence_4 = { 8be5 5d c3 66c78594fbffff6600 b903000000 8dbd90fbffff 8db5d0fbffff }
            // n = 7, score = 200
            //   8be5                 | mov                 esp, ebp
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   66c78594fbffff6600     | mov    word ptr [ebp - 0x46c], 0x66
            //   b903000000           | mov                 ecx, 3
            //   8dbd90fbffff         | lea                 edi, [ebp - 0x470]
            //   8db5d0fbffff         | lea                 esi, [ebp - 0x430]

        $sequence_5 = { 7502 eb17 8b45fc 83c00c 50 6a40 }
            // n = 6, score = 200
            //   7502                 | jne                 4
            //   eb17                 | jmp                 0x19
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   83c00c               | add                 eax, 0xc
            //   50                   | push                eax
            //   6a40                 | push                0x40

        $sequence_6 = { 66ab 6a32 aa ffd6 }
            // n = 4, score = 200
            //   66ab                 | stosw               word ptr es:[edi], ax
            //   6a32                 | push                0x32
            //   aa                   | stosb               byte ptr es:[edi], al
            //   ffd6                 | call                esi

        $sequence_7 = { 7364 8bfe 83c9ff f2ae f7d1 }
            // n = 5, score = 200
            //   7364                 | jae                 0x66
            //   8bfe                 | mov                 edi, esi
            //   83c9ff               | or                  ecx, 0xffffffff
            //   f2ae                 | repne scasb         al, byte ptr es:[edi]
            //   f7d1                 | not                 ecx

        $sequence_8 = { 897dfc 740c 57 ff15???????? 8365fc00 }
            // n = 5, score = 200
            //   897dfc               | mov                 dword ptr [ebp - 4], edi
            //   740c                 | je                  0xe
            //   57                   | push                edi
            //   ff15????????         |                     
            //   8365fc00             | and                 dword ptr [ebp - 4], 0

        $sequence_9 = { 33c0 8dbd92fbffff f3ab 66ab c7858cfbffff00000000 }
            // n = 5, score = 200
            //   33c0                 | xor                 eax, eax
            //   8dbd92fbffff         | lea                 edi, [ebp - 0x46e]
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax
            //   66ab                 | stosw               word ptr es:[edi], ax
            //   c7858cfbffff00000000     | mov    dword ptr [ebp - 0x474], 0

        $sequence_10 = { 0f84b8020000 3bfb 0f84b0020000 83ffff 0f84a7020000 83ff01 }
            // n = 6, score = 200
            //   0f84b8020000         | je                  0x2be
            //   3bfb                 | cmp                 edi, ebx
            //   0f84b0020000         | je                  0x2b6
            //   83ffff               | cmp                 edi, -1
            //   0f84a7020000         | je                  0x2ad
            //   83ff01               | cmp                 edi, 1

        $sequence_11 = { ffd3 8d45fc 897dfc 50 8d8620010000 50 8d45f8 }
            // n = 7, score = 200
            //   ffd3                 | call                ebx
            //   8d45fc               | lea                 eax, [ebp - 4]
            //   897dfc               | mov                 dword ptr [ebp - 4], edi
            //   50                   | push                eax
            //   8d8620010000         | lea                 eax, [esi + 0x120]
            //   50                   | push                eax
            //   8d45f8               | lea                 eax, [ebp - 8]

        $sequence_12 = { 8995dcfdffff c785d4fdffff00000000 837d1000 7417 8b4514 50 8b4d10 }
            // n = 7, score = 200
            //   8995dcfdffff         | mov                 dword ptr [ebp - 0x224], edx
            //   c785d4fdffff00000000     | mov    dword ptr [ebp - 0x22c], 0
            //   837d1000             | cmp                 dword ptr [ebp + 0x10], 0
            //   7417                 | je                  0x19
            //   8b4514               | mov                 eax, dword ptr [ebp + 0x14]
            //   50                   | push                eax
            //   8b4d10               | mov                 ecx, dword ptr [ebp + 0x10]

        $sequence_13 = { 50 8b4d08 51 e8???????? 83c40c 894508 }
            // n = 6, score = 200
            //   50                   | push                eax
            //   8b4d08               | mov                 ecx, dword ptr [ebp + 8]
            //   51                   | push                ecx
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   894508               | mov                 dword ptr [ebp + 8], eax

        $sequence_14 = { 57 85ed c744240c00000000 0f8402010000 }
            // n = 4, score = 200
            //   57                   | push                edi
            //   85ed                 | test                ebp, ebp
            //   c744240c00000000     | mov                 dword ptr [esp + 0xc], 0
            //   0f8402010000         | je                  0x108

        $sequence_15 = { aa 6a47 33c0 59 8dbdd5feffff f3ab 66ab }
            // n = 7, score = 200
            //   aa                   | stosb               byte ptr es:[edi], al
            //   6a47                 | push                0x47
            //   33c0                 | xor                 eax, eax
            //   59                   | pop                 ecx
            //   8dbdd5feffff         | lea                 edi, [ebp - 0x12b]
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax
            //   66ab                 | stosw               word ptr es:[edi], ax

    condition:
        7 of them and filesize < 368640
}