rule win_keylogger_apt3_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-04-08"
        version = "1"
        description = "Detects win.keylogger_apt3."
        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.keylogger_apt3"
        malpedia_rule_date = "20220405"
        malpedia_hash = "ecd38294bd47d5589be5cd5490dc8bb4804afc2a"
        malpedia_version = "20220411"
        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 = { 6a00 6a00 6a00 8bf8 a1???????? 50 6a01 }
            // n = 7, score = 300
            //   6a00                 | push                0
            //   6a00                 | push                0
            //   6a00                 | push                0
            //   8bf8                 | mov                 edi, eax
            //   a1????????           |                     
            //   50                   | push                eax
            //   6a01                 | push                1

        $sequence_1 = { 6a6c 51 8944242c c744243000000000 c7442434d8174300 }
            // n = 5, score = 300
            //   6a6c                 | push                0x6c
            //   51                   | push                ecx
            //   8944242c             | mov                 dword ptr [esp + 0x2c], eax
            //   c744243000000000     | mov                 dword ptr [esp + 0x30], 0
            //   c7442434d8174300     | mov                 dword ptr [esp + 0x34], 0x4317d8

        $sequence_2 = { e8???????? 8d9600020000 52 8d44242c 68???????? 50 ffd7 }
            // n = 7, score = 300
            //   e8????????           |                     
            //   8d9600020000         | lea                 edx, dword ptr [esi + 0x200]
            //   52                   | push                edx
            //   8d44242c             | lea                 eax, dword ptr [esp + 0x2c]
            //   68????????           |                     
            //   50                   | push                eax
            //   ffd7                 | call                edi

        $sequence_3 = { 7406 83784000 75c4 5e }
            // n = 4, score = 300
            //   7406                 | je                  8
            //   83784000             | cmp                 dword ptr [eax + 0x40], 0
            //   75c4                 | jne                 0xffffffc6
            //   5e                   | pop                 esi

        $sequence_4 = { 22d1 8810 897008 897010 }
            // n = 4, score = 300
            //   22d1                 | and                 dl, cl
            //   8810                 | mov                 byte ptr [eax], dl
            //   897008               | mov                 dword ptr [eax + 8], esi
            //   897010               | mov                 dword ptr [eax + 0x10], esi

        $sequence_5 = { 8b11 50 8b4204 ffd0 8b8c2488000000 64890d00000000 }
            // n = 6, score = 300
            //   8b11                 | mov                 edx, dword ptr [ecx]
            //   50                   | push                eax
            //   8b4204               | mov                 eax, dword ptr [edx + 4]
            //   ffd0                 | call                eax
            //   8b8c2488000000       | mov                 ecx, dword ptr [esp + 0x88]
            //   64890d00000000       | mov                 dword ptr fs:[0], ecx

        $sequence_6 = { 8d442420 50 ffd7 85c0 75cc 5f }
            // n = 6, score = 300
            //   8d442420             | lea                 eax, dword ptr [esp + 0x20]
            //   50                   | push                eax
            //   ffd7                 | call                edi
            //   85c0                 | test                eax, eax
            //   75cc                 | jne                 0xffffffce
            //   5f                   | pop                 edi

        $sequence_7 = { c644241535 884c2416 88442417 c644241832 c644241931 c644241a32 8844241b }
            // n = 7, score = 300
            //   c644241535           | mov                 byte ptr [esp + 0x15], 0x35
            //   884c2416             | mov                 byte ptr [esp + 0x16], cl
            //   88442417             | mov                 byte ptr [esp + 0x17], al
            //   c644241832           | mov                 byte ptr [esp + 0x18], 0x32
            //   c644241931           | mov                 byte ptr [esp + 0x19], 0x31
            //   c644241a32           | mov                 byte ptr [esp + 0x1a], 0x32
            //   8844241b             | mov                 byte ptr [esp + 0x1b], al

        $sequence_8 = { 56 e8???????? 83c414 85c0 74cb 0fb644240f 297c241c }
            // n = 7, score = 300
            //   56                   | push                esi
            //   e8????????           |                     
            //   83c414               | add                 esp, 0x14
            //   85c0                 | test                eax, eax
            //   74cb                 | je                  0xffffffcd
            //   0fb644240f           | movzx               eax, byte ptr [esp + 0xf]
            //   297c241c             | sub                 dword ptr [esp + 0x1c], edi

        $sequence_9 = { 741f 8bc2 8d7001 8da42400000000 }
            // n = 4, score = 300
            //   741f                 | je                  0x21
            //   8bc2                 | mov                 eax, edx
            //   8d7001               | lea                 esi, dword ptr [eax + 1]
            //   8da42400000000       | lea                 esp, dword ptr [esp]

    condition:
        7 of them and filesize < 761856
}