rule win_netrepser_keylogger_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.netrepser_keylogger."
        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.netrepser_keylogger"
        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 = { 3b45f8 7d6c c785ecfeffff00000000 eb0f 8b8decfeffff 83c101 }
            // n = 6, score = 200
            //   3b45f8               | cmp                 eax, dword ptr [ebp - 8]
            //   7d6c                 | jge                 0x6e
            //   c785ecfeffff00000000     | mov    dword ptr [ebp - 0x114], 0
            //   eb0f                 | jmp                 0x11
            //   8b8decfeffff         | mov                 ecx, dword ptr [ebp - 0x114]
            //   83c101               | add                 ecx, 1

        $sequence_1 = { 817dfc18030980 7579 6a00 8b4d18 }
            // n = 4, score = 200
            //   817dfc18030980       | cmp                 dword ptr [ebp - 4], 0x80090318
            //   7579                 | jne                 0x7b
            //   6a00                 | push                0
            //   8b4d18               | mov                 ecx, dword ptr [ebp + 0x18]

        $sequence_2 = { 8945fc 6a00 6a01 6a02 e8???????? }
            // n = 5, score = 200
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   6a00                 | push                0
            //   6a01                 | push                1
            //   6a02                 | push                2
            //   e8????????           |                     

        $sequence_3 = { 034510 034510 8945fc e9???????? }
            // n = 4, score = 200
            //   034510               | add                 eax, dword ptr [ebp + 0x10]
            //   034510               | add                 eax, dword ptr [ebp + 0x10]
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   e9????????           |                     

        $sequence_4 = { 8995dcfeffff 6a00 68100e0000 8b95dcfeffff 52 8b85d8feffff 50 }
            // n = 7, score = 200
            //   8995dcfeffff         | mov                 dword ptr [ebp - 0x124], edx
            //   6a00                 | push                0
            //   68100e0000           | push                0xe10
            //   8b95dcfeffff         | mov                 edx, dword ptr [ebp - 0x124]
            //   52                   | push                edx
            //   8b85d8feffff         | mov                 eax, dword ptr [ebp - 0x128]
            //   50                   | push                eax

        $sequence_5 = { 8b4508 50 ff15???????? e9???????? 8d4de0 51 8b5508 }
            // n = 7, score = 200
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   50                   | push                eax
            //   ff15????????         |                     
            //   e9????????           |                     
            //   8d4de0               | lea                 ecx, [ebp - 0x20]
            //   51                   | push                ecx
            //   8b5508               | mov                 edx, dword ptr [ebp + 8]

        $sequence_6 = { 52 6a10 6a00 8b45b4 50 6a00 }
            // n = 6, score = 200
            //   52                   | push                edx
            //   6a10                 | push                0x10
            //   6a00                 | push                0
            //   8b45b4               | mov                 eax, dword ptr [ebp - 0x4c]
            //   50                   | push                eax
            //   6a00                 | push                0

        $sequence_7 = { 52 68e9fd0000 e8???????? 83c40c }
            // n = 4, score = 200
            //   52                   | push                edx
            //   68e9fd0000           | push                0xfde9
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc

        $sequence_8 = { c744240846726565 c744240c5265736f c744241075726365 c744241400000000 ff15???????? }
            // n = 5, score = 100
            //   c744240846726565     | mov                 dword ptr [esp + 8], 0x65657246
            //   c744240c5265736f     | mov                 dword ptr [esp + 0xc], 0x6f736552
            //   c744241075726365     | mov                 dword ptr [esp + 0x10], 0x65637275
            //   c744241400000000     | mov                 dword ptr [esp + 0x14], 0
            //   ff15????????         |                     

        $sequence_9 = { 89551c c6452000 6a3f 6a00 }
            // n = 4, score = 100
            //   89551c               | mov                 dword ptr [ebp + 0x1c], edx
            //   c6452000             | mov                 byte ptr [ebp + 0x20], 0
            //   6a3f                 | push                0x3f
            //   6a00                 | push                0

        $sequence_10 = { 8904bd70584000 8b4c2448 5e 5b }
            // n = 4, score = 100
            //   8904bd70584000       | mov                 dword ptr [edi*4 + 0x405870], eax
            //   8b4c2448             | mov                 ecx, dword ptr [esp + 0x48]
            //   5e                   | pop                 esi
            //   5b                   | pop                 ebx

        $sequence_11 = { 7537 3905???????? 7509 57 }
            // n = 4, score = 100
            //   7537                 | jne                 0x39
            //   3905????????         |                     
            //   7509                 | jne                 0xb
            //   57                   | push                edi

        $sequence_12 = { e8???????? 83c418 85c0 7662 50 }
            // n = 5, score = 100
            //   e8????????           |                     
            //   83c418               | add                 esp, 0x18
            //   85c0                 | test                eax, eax
            //   7662                 | jbe                 0x64
            //   50                   | push                eax

        $sequence_13 = { 8975fc 3bc6 0f84f0010000 3bde 0f84e8010000 397570 0f84df010000 }
            // n = 7, score = 100
            //   8975fc               | mov                 dword ptr [ebp - 4], esi
            //   3bc6                 | cmp                 eax, esi
            //   0f84f0010000         | je                  0x1f6
            //   3bde                 | cmp                 ebx, esi
            //   0f84e8010000         | je                  0x1ee
            //   397570               | cmp                 dword ptr [ebp + 0x70], esi
            //   0f84df010000         | je                  0x1e5

        $sequence_14 = { ff15???????? 8b442414 6683f809 7505 bd02000000 5b e8???????? }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   8b442414             | mov                 eax, dword ptr [esp + 0x14]
            //   6683f809             | cmp                 ax, 9
            //   7505                 | jne                 7
            //   bd02000000           | mov                 ebp, 2
            //   5b                   | pop                 ebx
            //   e8????????           |                     

        $sequence_15 = { 51 8d561a 52 c64619b8 e8???????? 83c448 c6461eff }
            // n = 7, score = 100
            //   51                   | push                ecx
            //   8d561a               | lea                 edx, [esi + 0x1a]
            //   52                   | push                edx
            //   c64619b8             | mov                 byte ptr [esi + 0x19], 0xb8
            //   e8????????           |                     
            //   83c448               | add                 esp, 0x48
            //   c6461eff             | mov                 byte ptr [esi + 0x1e], 0xff

    condition:
        7 of them and filesize < 303104
}