rule win_data_exfiltrator_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.data_exfiltrator."
        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.data_exfiltrator"
        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 = { 0fb70424 0fb74c2404 3bc1 7402 }
            // n = 4, score = 100
            //   0fb70424             | dec                 eax
            //   0fb74c2404           | lea                 edx, [esp + 0x30]
            //   3bc1                 | dec                 eax
            //   7402                 | mov                 ecx, dword ptr [esp + 0x140]

        $sequence_1 = { 89442420 4863442420 4889442438 ff15???????? 488b4c2438 4c8bc1 ba08000000 }
            // n = 7, score = 100
            //   89442420             | mov                 dword ptr [esp + 0x30], 0
            //   4863442420           | ret                 
            //   4889442438           | inc                 esp
            //   ff15????????         |                     
            //   488b4c2438           | mov                 dword ptr [esp + 0x20], ecx
            //   4c8bc1               | inc                 esp
            //   ba08000000           | mov                 dword ptr [esp + 0x18], eax

        $sequence_2 = { 41b8ffffffff 488d15d32a0000 488b4c2448 ff15???????? 48837c244800 0f84b2000000 8b8424c8000000 }
            // n = 7, score = 100
            //   41b8ffffffff         | mov                 ecx, dword ptr [esp + 0x10]
            //   488d15d32a0000       | dec                 eax
            //   488b4c2448           | dec                 ecx
            //   ff15????????         |                     
            //   48837c244800         | dec                 eax
            //   0f84b2000000         | not                 ecx
            //   8b8424c8000000       | dec                 eax

        $sequence_3 = { c644245d78 c644245e00 488d4c2440 e8???????? }
            // n = 4, score = 100
            //   c644245d78           | dec                 eax
            //   c644245e00           | not                 ecx
            //   488d4c2440           | dec                 eax
            //   e8????????           |                     

        $sequence_4 = { c644244d78 c644244e7a c644244f62 c644245075 }
            // n = 4, score = 100
            //   c644244d78           | dec                 eax
            //   c644244e7a           | mov                 eax, dword ptr [esp + 0x60]
            //   c644244f62           | dec                 eax
            //   c644245075           | mov                 eax, dword ptr [eax + 0x4010]

        $sequence_5 = { 488b8c24b0000000 e8???????? 48898424a8000000 488b8424a8000000 8b00 4533c0 }
            // n = 6, score = 100
            //   488b8c24b0000000     | mov                 byte ptr [esp + 0x70], 0x7a
            //   e8????????           |                     
            //   48898424a8000000     | mov                 byte ptr [esp + 0x6d], 0
            //   488b8424a8000000     | dec                 eax
            //   8b00                 | lea                 ecx, [esp + 0x48]
            //   4533c0               | mov                 byte ptr [esp + 0x20], 0xfb

        $sequence_6 = { 488bc1 4889442430 488b542430 488b4c2450 ff542470 8944242c 837c242c00 }
            // n = 7, score = 100
            //   488bc1               | mov                 dword ptr [esp + 0x38], 0
            //   4889442430           | mov                 edx, 0xffff
            //   488b542430           | dec                 eax
            //   488b4c2450           | lea                 ecx, [esp + 0x30]
            //   ff542470             | jle                 0x118c
            //   8944242c             | mov                 dword ptr [esp + 0x24], 0x7f17
            //   837c242c00           | jmp                 0x1194

        $sequence_7 = { ff15???????? 33c0 e9???????? e9???????? 4533c0 33d2 b900000400 }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   33c0                 | movzx               eax, byte ptr [ecx + eax]
            //   e9????????           |                     
            //   e9????????           |                     
            //   4533c0               | mov                 ecx, dword ptr [esp + 4]
            //   33d2                 | mov                 dword ptr [esp + ecx*4 + 0x10], eax
            //   b900000400           | cmp                 dword ptr [esp + 0x20], eax

        $sequence_8 = { 83e830 89442428 837c242800 7c3a 8b442448 39442428 7d30 }
            // n = 7, score = 100
            //   83e830               | lea                 edx, [0x574b]
            //   89442428             | dec                 eax
            //   837c242800           | mov                 ecx, dword ptr [esp + 0x20]
            //   7c3a                 | mov                 ecx, 0x9f17
            //   8b442448             | dec                 eax
            //   39442428             | mov                 dword ptr [esp + 0x20], eax
            //   7d30                 | inc                 ecx

        $sequence_9 = { c6442420fb c6442421fc c6442422fe c6442423ff c6442424aa c644242548 }
            // n = 6, score = 100
            //   c6442420fb           | inc                 eax
            //   c6442421fc           | push                esi
            //   c6442422fe           | push                edi
            //   c6442423ff           | dec                 eax
            //   c6442424aa           | sub                 esp, 0xf8
            //   c644242548           | mov                 dword ptr [esp + 0x20], 0

    condition:
        7 of them and filesize < 107520
}