rule win_conficker_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2021-06-10"
        version = "1"
        description = "Detects win.conficker."
        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.conficker"
        malpedia_rule_date = "20210604"
        malpedia_hash = "be09d5d71e77373c0f538068be31a2ad4c69cfbd"
        malpedia_version = "20210616"
        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 = { 7502 4a 4a 3c09 740d 2c05 }
            // n = 6, score = 300
            //   7502                 | jne                 4
            //   4a                   | dec                 edx
            //   4a                   | dec                 edx
            //   3c09                 | cmp                 al, 9
            //   740d                 | je                  0xf
            //   2c05                 | sub                 al, 5

        $sequence_1 = { 8bd1 81e2ffff0000 40 81fac0a80000 7413 80f90a }
            // n = 6, score = 300
            //   8bd1                 | mov                 edx, ecx
            //   81e2ffff0000         | and                 edx, 0xffff
            //   40                   | inc                 eax
            //   81fac0a80000         | cmp                 edx, 0xa8c0
            //   7413                 | je                  0x15
            //   80f90a               | cmp                 cl, 0xa

        $sequence_2 = { ebe4 f60638 75a8 b008 d0ef 1400 }
            // n = 6, score = 300
            //   ebe4                 | jmp                 0xffffffe6
            //   f60638               | test                byte ptr [esi], 0x38
            //   75a8                 | jne                 0xffffffaa
            //   b008                 | mov                 al, 8
            //   d0ef                 | shr                 bh, 1
            //   1400                 | adc                 al, 0

        $sequence_3 = { 51 51 56 57 ff15???????? 8bf0 ff15???????? }
            // n = 7, score = 300
            //   51                   | push                ecx
            //   51                   | push                ecx
            //   56                   | push                esi
            //   57                   | push                edi
            //   ff15????????         |                     
            //   8bf0                 | mov                 esi, eax
            //   ff15????????         |                     

        $sequence_4 = { 47 3b7d10 7cca 5e }
            // n = 4, score = 300
            //   47                   | inc                 edi
            //   3b7d10               | cmp                 edi, dword ptr [ebp + 0x10]
            //   7cca                 | jl                  0xffffffcc
            //   5e                   | pop                 esi

        $sequence_5 = { 7209 770e 49 79f1 }
            // n = 4, score = 300
            //   7209                 | jb                  0xb
            //   770e                 | ja                  0x10
            //   49                   | dec                 ecx
            //   79f1                 | jns                 0xfffffff3

        $sequence_6 = { e8???????? 8bd0 83c410 85d2 0f8c9c000000 }
            // n = 5, score = 300
            //   e8????????           |                     
            //   8bd0                 | mov                 edx, eax
            //   83c410               | add                 esp, 0x10
            //   85d2                 | test                edx, edx
            //   0f8c9c000000         | jl                  0xa2

        $sequence_7 = { 894dfc 2175fc d9e0 23cf dec1 8945e8 894dec }
            // n = 7, score = 300
            //   894dfc               | mov                 dword ptr [ebp - 4], ecx
            //   2175fc               | and                 dword ptr [ebp - 4], esi
            //   d9e0                 | fchs                
            //   23cf                 | and                 ecx, edi
            //   dec1                 | faddp               st(1)
            //   8945e8               | mov                 dword ptr [ebp - 0x18], eax
            //   894dec               | mov                 dword ptr [ebp - 0x14], ecx

        $sequence_8 = { 3c01 74db 81c751000000 3c0a 74d4 8b7d24 }
            // n = 6, score = 300
            //   3c01                 | cmp                 al, 1
            //   74db                 | je                  0xffffffdd
            //   81c751000000         | add                 edi, 0x51
            //   3c0a                 | cmp                 al, 0xa
            //   74d4                 | je                  0xffffffd6
            //   8b7d24               | mov                 edi, dword ptr [ebp + 0x24]

        $sequence_9 = { 3b7510 891f 894c9008 7c02 33f6 }
            // n = 5, score = 300
            //   3b7510               | cmp                 esi, dword ptr [ebp + 0x10]
            //   891f                 | mov                 dword ptr [edi], ebx
            //   894c9008             | mov                 dword ptr [eax + edx*4 + 8], ecx
            //   7c02                 | jl                  4
            //   33f6                 | xor                 esi, esi

    condition:
        7 of them and filesize < 335872
}