rule win_coredn_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-08-05"
        version = "1"
        description = "Detects win.coredn."
        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.coredn"
        malpedia_rule_date = "20220805"
        malpedia_hash = "6ec06c64bcfdbeda64eff021c766b4ce34542b71"
        malpedia_version = "20220808"
        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 = { 51 56 8d45fc 8bf1 50 e8???????? 85c0 }
            // n = 7, score = 600
            //   51                   | push                ecx
            //   56                   | push                esi
            //   8d45fc               | lea                 eax, [ebp - 4]
            //   8bf1                 | mov                 esi, ecx
            //   50                   | push                eax
            //   e8????????           |                     
            //   85c0                 | test                eax, eax

        $sequence_1 = { 83c404 894e0c 85c9 7507 5f }
            // n = 5, score = 400
            //   83c404               | add                 esp, 4
            //   894e0c               | mov                 dword ptr [esi + 0xc], ecx
            //   85c9                 | test                ecx, ecx
            //   7507                 | jne                 9
            //   5f                   | pop                 edi

        $sequence_2 = { e8???????? 83c408 8b460c 5e 85c0 740b 6a02 }
            // n = 7, score = 400
            //   e8????????           |                     
            //   83c408               | add                 esp, 8
            //   8b460c               | mov                 eax, dword ptr [esi + 0xc]
            //   5e                   | pop                 esi
            //   85c0                 | test                eax, eax
            //   740b                 | je                  0xd
            //   6a02                 | push                2

        $sequence_3 = { 7456 8bcb 8d5101 6690 8a01 41 }
            // n = 6, score = 400
            //   7456                 | je                  0x58
            //   8bcb                 | mov                 ecx, ebx
            //   8d5101               | lea                 edx, [ecx + 1]
            //   6690                 | nop                 
            //   8a01                 | mov                 al, byte ptr [ecx]
            //   41                   | inc                 ecx

        $sequence_4 = { ba04010000 2bf1 6690 8d82fafeff7f 85c0 741c 8a040e }
            // n = 7, score = 400
            //   ba04010000           | mov                 edx, 0x104
            //   2bf1                 | sub                 esi, ecx
            //   6690                 | nop                 
            //   8d82fafeff7f         | lea                 eax, [edx + 0x7ffffefa]
            //   85c0                 | test                eax, eax
            //   741c                 | je                  0x1e
            //   8a040e               | mov                 al, byte ptr [esi + ecx]

        $sequence_5 = { 8a1c06 84db 741c 8818 4a }
            // n = 5, score = 400
            //   8a1c06               | mov                 bl, byte ptr [esi + eax]
            //   84db                 | test                bl, bl
            //   741c                 | je                  0x1e
            //   8818                 | mov                 byte ptr [eax], bl
            //   4a                   | dec                 edx

        $sequence_6 = { 5f 5b 5e 8be5 5d c20400 85c9 }
            // n = 7, score = 400
            //   5f                   | pop                 edi
            //   5b                   | pop                 ebx
            //   5e                   | pop                 esi
            //   8be5                 | mov                 esp, ebp
            //   5d                   | pop                 ebp
            //   c20400               | ret                 4
            //   85c9                 | test                ecx, ecx

        $sequence_7 = { 750d 8851ff b87a000780 5e 5d c20400 }
            // n = 6, score = 400
            //   750d                 | jne                 0xf
            //   8851ff               | mov                 byte ptr [ecx - 1], dl
            //   b87a000780           | mov                 eax, 0x8007007a
            //   5e                   | pop                 esi
            //   5d                   | pop                 ebp
            //   c20400               | ret                 4

        $sequence_8 = { 5d c20400 85d2 7506 49 bb7a000780 }
            // n = 6, score = 400
            //   5d                   | pop                 ebp
            //   c20400               | ret                 4
            //   85d2                 | test                edx, edx
            //   7506                 | jne                 8
            //   49                   | dec                 ecx
            //   bb7a000780           | mov                 ebx, 0x8007007a

        $sequence_9 = { 33d2 0f1f440000 3811 7408 41 }
            // n = 5, score = 400
            //   33d2                 | xor                 edx, edx
            //   0f1f440000           | nop                 dword ptr [eax + eax]
            //   3811                 | cmp                 byte ptr [ecx], dl
            //   7408                 | je                  0xa
            //   41                   | inc                 ecx

        $sequence_10 = { 2bf0 85d2 7423 8a1c06 }
            // n = 4, score = 400
            //   2bf0                 | sub                 esi, eax
            //   85d2                 | test                edx, edx
            //   7423                 | je                  0x25
            //   8a1c06               | mov                 bl, byte ptr [esi + eax]

        $sequence_11 = { 85c0 740b 6a01 50 e8???????? 83c408 8b44241c }
            // n = 7, score = 400
            //   85c0                 | test                eax, eax
            //   740b                 | je                  0xd
            //   6a01                 | push                1
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c408               | add                 esp, 8
            //   8b44241c             | mov                 eax, dword ptr [esp + 0x1c]

        $sequence_12 = { 84c0 7415 8801 41 83ea01 75e7 }
            // n = 6, score = 400
            //   84c0                 | test                al, al
            //   7415                 | je                  0x17
            //   8801                 | mov                 byte ptr [ecx], al
            //   41                   | inc                 ecx
            //   83ea01               | sub                 edx, 1
            //   75e7                 | jne                 0xffffffe9

        $sequence_13 = { 75f9 2bd1 0f84b9000000 8b460c }
            // n = 4, score = 400
            //   75f9                 | jne                 0xfffffffb
            //   2bd1                 | sub                 edx, ecx
            //   0f84b9000000         | je                  0xbf
            //   8b460c               | mov                 eax, dword ptr [esi + 0xc]

        $sequence_14 = { 85d2 7438 8b7d08 befeffff7f 2bf2 2bf9 90 }
            // n = 7, score = 400
            //   85d2                 | test                edx, edx
            //   7438                 | je                  0x3a
            //   8b7d08               | mov                 edi, dword ptr [ebp + 8]
            //   befeffff7f           | mov                 esi, 0x7ffffffe
            //   2bf2                 | sub                 esi, edx
            //   2bf9                 | sub                 edi, ecx
            //   90                   | nop                 

        $sequence_15 = { 7408 81faffffff7f 7605 b857000780 85c0 784f }
            // n = 6, score = 400
            //   7408                 | je                  0xa
            //   81faffffff7f         | cmp                 edx, 0x7fffffff
            //   7605                 | jbe                 7
            //   b857000780           | mov                 eax, 0x80070057
            //   85c0                 | test                eax, eax
            //   784f                 | js                  0x51

    condition:
        7 of them and filesize < 385024
}