rule win_scarecrow_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.scarecrow."
        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.scarecrow"
        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 = { f7fe 85d2 7521 b905000000 8b45f4 99 f7f9 }
            // n = 7, score = 100
            //   f7fe                 | idiv                esi
            //   85d2                 | test                edx, edx
            //   7521                 | jne                 0x23
            //   b905000000           | mov                 ecx, 5
            //   8b45f4               | mov                 eax, dword ptr [ebp - 0xc]
            //   99                   | cdq                 
            //   f7f9                 | idiv                ecx

        $sequence_1 = { 889435d5f9ffff 46 83fe0c 72d3 8d85d5f9ffff 8985e0f6ffff c685f8faffff00 }
            // n = 7, score = 100
            //   889435d5f9ffff       | mov                 byte ptr [ebp + esi - 0x62b], dl
            //   46                   | inc                 esi
            //   83fe0c               | cmp                 esi, 0xc
            //   72d3                 | jb                  0xffffffd5
            //   8d85d5f9ffff         | lea                 eax, [ebp - 0x62b]
            //   8985e0f6ffff         | mov                 dword ptr [ebp - 0x920], eax
            //   c685f8faffff00       | mov                 byte ptr [ebp - 0x508], 0

        $sequence_2 = { c6458a37 c6458b0e c6458c69 c6458d01 c6458e28 8a854dffffff e8???????? }
            // n = 7, score = 100
            //   c6458a37             | mov                 byte ptr [ebp - 0x76], 0x37
            //   c6458b0e             | mov                 byte ptr [ebp - 0x75], 0xe
            //   c6458c69             | mov                 byte ptr [ebp - 0x74], 0x69
            //   c6458d01             | mov                 byte ptr [ebp - 0x73], 1
            //   c6458e28             | mov                 byte ptr [ebp - 0x72], 0x28
            //   8a854dffffff         | mov                 al, byte ptr [ebp - 0xb3]
            //   e8????????           |                     

        $sequence_3 = { f7fb 8b45f0 c1e602 8975ec 85d2 743f }
            // n = 6, score = 100
            //   f7fb                 | idiv                ebx
            //   8b45f0               | mov                 eax, dword ptr [ebp - 0x10]
            //   c1e602               | shl                 esi, 2
            //   8975ec               | mov                 dword ptr [ebp - 0x14], esi
            //   85d2                 | test                edx, edx
            //   743f                 | je                  0x41

        $sequence_4 = { 40 74dd a1???????? 8b4df8 5f 893401 8bc6 }
            // n = 7, score = 100
            //   40                   | inc                 eax
            //   74dd                 | je                  0xffffffdf
            //   a1????????           |                     
            //   8b4df8               | mov                 ecx, dword ptr [ebp - 8]
            //   5f                   | pop                 edi
            //   893401               | mov                 dword ptr [ecx + eax], esi
            //   8bc6                 | mov                 eax, esi

        $sequence_5 = { c6458f0d 89852cffffff c6459044 8a4585 e8???????? c645e800 c645e900 }
            // n = 7, score = 100
            //   c6458f0d             | mov                 byte ptr [ebp - 0x71], 0xd
            //   89852cffffff         | mov                 dword ptr [ebp - 0xd4], eax
            //   c6459044             | mov                 byte ptr [ebp - 0x70], 0x44
            //   8a4585               | mov                 al, byte ptr [ebp - 0x7b]
            //   e8????????           |                     
            //   c645e800             | mov                 byte ptr [ebp - 0x18], 0
            //   c645e900             | mov                 byte ptr [ebp - 0x17], 0

        $sequence_6 = { f7fb 8d427f 99 f7fb 889435a5faffff 46 }
            // n = 6, score = 100
            //   f7fb                 | idiv                ebx
            //   8d427f               | lea                 eax, [edx + 0x7f]
            //   99                   | cdq                 
            //   f7fb                 | idiv                ebx
            //   889435a5faffff       | mov                 byte ptr [ebp + esi - 0x55b], dl
            //   46                   | inc                 esi

        $sequence_7 = { c685c0fdffff25 c685c1fdffff7c c685c2fdffff25 c685c3fdffff36 c685c4fdffff25 c685c5fdffff25 }
            // n = 6, score = 100
            //   c685c0fdffff25       | mov                 byte ptr [ebp - 0x240], 0x25
            //   c685c1fdffff7c       | mov                 byte ptr [ebp - 0x23f], 0x7c
            //   c685c2fdffff25       | mov                 byte ptr [ebp - 0x23e], 0x25
            //   c685c3fdffff36       | mov                 byte ptr [ebp - 0x23d], 0x36
            //   c685c4fdffff25       | mov                 byte ptr [ebp - 0x23c], 0x25
            //   c685c5fdffff25       | mov                 byte ptr [ebp - 0x23b], 0x25

        $sequence_8 = { 83c8fe 40 7579 b905000000 0f1f440000 8b45f4 99 }
            // n = 7, score = 100
            //   83c8fe               | or                  eax, 0xfffffffe
            //   40                   | inc                 eax
            //   7579                 | jne                 0x7b
            //   b905000000           | mov                 ecx, 5
            //   0f1f440000           | nop                 dword ptr [eax + eax]
            //   8b45f4               | mov                 eax, dword ptr [ebp - 0xc]
            //   99                   | cdq                 

        $sequence_9 = { 6685c0 75f5 2bce d1f9 51 8d45c9 8bca }
            // n = 7, score = 100
            //   6685c0               | test                ax, ax
            //   75f5                 | jne                 0xfffffff7
            //   2bce                 | sub                 ecx, esi
            //   d1f9                 | sar                 ecx, 1
            //   51                   | push                ecx
            //   8d45c9               | lea                 eax, [ebp - 0x37]
            //   8bca                 | mov                 ecx, edx

    condition:
        7 of them and filesize < 501760
}