rule win_ddkeylogger_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.ddkeylogger."
        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.ddkeylogger"
        malpedia_rule_date = "20230124"
        malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686"
        malpedia_version = "20230125"
        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 = { 8bc2 c1e802 8a0430 83e203 8801 c1e204 8bc7 }
            // n = 7, score = 200
            //   8bc2                 | mov                 eax, edx
            //   c1e802               | shr                 eax, 2
            //   8a0430               | mov                 al, byte ptr [eax + esi]
            //   83e203               | and                 edx, 3
            //   8801                 | mov                 byte ptr [ecx], al
            //   c1e204               | shl                 edx, 4
            //   8bc7                 | mov                 eax, edi

        $sequence_1 = { 8810 40 49 75f7 8b45fc 8b4df8 }
            // n = 6, score = 200
            //   8810                 | mov                 byte ptr [eax], dl
            //   40                   | inc                 eax
            //   49                   | dec                 ecx
            //   75f7                 | jne                 0xfffffff9
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   8b4df8               | mov                 ecx, dword ptr [ebp - 8]

        $sequence_2 = { 6a00 ff15???????? 85c0 0f8832010000 56 8d45fc }
            // n = 6, score = 200
            //   6a00                 | push                0
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   0f8832010000         | js                  0x138
            //   56                   | push                esi
            //   8d45fc               | lea                 eax, [ebp - 4]

        $sequence_3 = { e8???????? 83c410 8b4704 0307 0fb65708 0fb60b 894510 }
            // n = 7, score = 200
            //   e8????????           |                     
            //   83c410               | add                 esp, 0x10
            //   8b4704               | mov                 eax, dword ptr [edi + 4]
            //   0307                 | add                 eax, dword ptr [edi]
            //   0fb65708             | movzx               edx, byte ptr [edi + 8]
            //   0fb60b               | movzx               ecx, byte ptr [ebx]
            //   894510               | mov                 dword ptr [ebp + 0x10], eax

        $sequence_4 = { ff15???????? 8d9554fcffff 52 8d8564fcffff 50 6a00 6a00 }
            // n = 7, score = 200
            //   ff15????????         |                     
            //   8d9554fcffff         | lea                 edx, [ebp - 0x3ac]
            //   52                   | push                edx
            //   8d8564fcffff         | lea                 eax, [ebp - 0x39c]
            //   50                   | push                eax
            //   6a00                 | push                0
            //   6a00                 | push                0

        $sequence_5 = { 8d9560fbffff 6a00 52 e8???????? 83c444 c705????????00000000 }
            // n = 6, score = 200
            //   8d9560fbffff         | lea                 edx, [ebp - 0x4a0]
            //   6a00                 | push                0
            //   52                   | push                edx
            //   e8????????           |                     
            //   83c444               | add                 esp, 0x44
            //   c705????????00000000     |     

        $sequence_6 = { 83e61f 8d3c8580ee4500 8b07 c1e606 8a4c3004 f6c101 7514 }
            // n = 7, score = 200
            //   83e61f               | and                 esi, 0x1f
            //   8d3c8580ee4500       | lea                 edi, [eax*4 + 0x45ee80]
            //   8b07                 | mov                 eax, dword ptr [edi]
            //   c1e606               | shl                 esi, 6
            //   8a4c3004             | mov                 cl, byte ptr [eax + esi + 4]
            //   f6c101               | test                cl, 1
            //   7514                 | jne                 0x16

        $sequence_7 = { 83c102 48 75eb 8b4db8 5f 5e }
            // n = 6, score = 200
            //   83c102               | add                 ecx, 2
            //   48                   | dec                 eax
            //   75eb                 | jne                 0xffffffed
            //   8b4db8               | mov                 ecx, dword ptr [ebp - 0x48]
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi

        $sequence_8 = { 3d00002003 7312 6a00 6a00 }
            // n = 4, score = 200
            //   3d00002003           | cmp                 eax, 0x3200000
            //   7312                 | jae                 0x14
            //   6a00                 | push                0
            //   6a00                 | push                0

        $sequence_9 = { 56 ff15???????? 56 8bf8 ff15???????? 3b3d???????? }
            // n = 6, score = 200
            //   56                   | push                esi
            //   ff15????????         |                     
            //   56                   | push                esi
            //   8bf8                 | mov                 edi, eax
            //   ff15????????         |                     
            //   3b3d????????         |                     

    condition:
        7 of them and filesize < 808960
}