rule win_cookiebag_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.cookiebag."
        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.cookiebag"
        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 = { e8???????? 68???????? e8???????? 83c404 8d4c242c 50 8b442438 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   68????????           |                     
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   8d4c242c             | lea                 ecx, [esp + 0x2c]
            //   50                   | push                eax
            //   8b442438             | mov                 eax, dword ptr [esp + 0x38]

        $sequence_1 = { 81e6ff000000 8bc6 2bca c1e802 83f901 8a5c042c 7705 }
            // n = 7, score = 100
            //   81e6ff000000         | and                 esi, 0xff
            //   8bc6                 | mov                 eax, esi
            //   2bca                 | sub                 ecx, edx
            //   c1e802               | shr                 eax, 2
            //   83f901               | cmp                 ecx, 1
            //   8a5c042c             | mov                 bl, byte ptr [esp + eax + 0x2c]
            //   7705                 | ja                  7

        $sequence_2 = { 89642424 6a00 8806 8bce e8???????? 8b0d???????? 51 }
            // n = 7, score = 100
            //   89642424             | mov                 dword ptr [esp + 0x24], esp
            //   6a00                 | push                0
            //   8806                 | mov                 byte ptr [esi], al
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     
            //   8b0d????????         |                     
            //   51                   | push                ecx

        $sequence_3 = { c744247c00310000 e8???????? c744247000000000 8b35???????? 8b442470 8bc8 40 }
            // n = 7, score = 100
            //   c744247c00310000     | mov                 dword ptr [esp + 0x7c], 0x3100
            //   e8????????           |                     
            //   c744247000000000     | mov                 dword ptr [esp + 0x70], 0
            //   8b35????????         |                     
            //   8b442470             | mov                 eax, dword ptr [esp + 0x70]
            //   8bc8                 | mov                 ecx, eax
            //   40                   | inc                 eax

        $sequence_4 = { 8b4508 51 50 50 e8???????? 83c40c 8bf8 }
            // n = 7, score = 100
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   51                   | push                ecx
            //   50                   | push                eax
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   8bf8                 | mov                 edi, eax

        $sequence_5 = { e8???????? 83c404 8bc5 8b8c24a0000000 5f 5e 5d }
            // n = 7, score = 100
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   8bc5                 | mov                 eax, ebp
            //   8b8c24a0000000       | mov                 ecx, dword ptr [esp + 0xa0]
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   5d                   | pop                 ebp

        $sequence_6 = { f3a4 8b4c2430 89442434 881c08 bf???????? 83c9ff 33c0 }
            // n = 7, score = 100
            //   f3a4                 | rep movsb           byte ptr es:[edi], byte ptr [esi]
            //   8b4c2430             | mov                 ecx, dword ptr [esp + 0x30]
            //   89442434             | mov                 dword ptr [esp + 0x34], eax
            //   881c08               | mov                 byte ptr [eax + ecx], bl
            //   bf????????           |                     
            //   83c9ff               | or                  ecx, 0xffffffff
            //   33c0                 | xor                 eax, eax

        $sequence_7 = { 8d8c2480000000 c684246001000018 51 8b4d28 e8???????? 68???????? }
            // n = 6, score = 100
            //   8d8c2480000000       | lea                 ecx, [esp + 0x80]
            //   c684246001000018     | mov                 byte ptr [esp + 0x160], 0x18
            //   51                   | push                ecx
            //   8b4d28               | mov                 ecx, dword ptr [ebp + 0x28]
            //   e8????????           |                     
            //   68????????           |                     

        $sequence_8 = { 8bcd 50 c744244400000000 e8???????? 8b0d???????? c644244001 51 }
            // n = 7, score = 100
            //   8bcd                 | mov                 ecx, ebp
            //   50                   | push                eax
            //   c744244400000000     | mov                 dword ptr [esp + 0x44], 0
            //   e8????????           |                     
            //   8b0d????????         |                     
            //   c644244001           | mov                 byte ptr [esp + 0x40], 1
            //   51                   | push                ecx

        $sequence_9 = { c68424e800000010 51 6a00 50 8d4d30 }
            // n = 5, score = 100
            //   c68424e800000010     | mov                 byte ptr [esp + 0xe8], 0x10
            //   51                   | push                ecx
            //   6a00                 | push                0
            //   50                   | push                eax
            //   8d4d30               | lea                 ecx, [ebp + 0x30]

    condition:
        7 of them and filesize < 311296
}