rule win_systembc_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-11-21"
        version = "1"
        description = "Detects win.systembc."
        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.systembc"
        malpedia_rule_date = "20221118"
        malpedia_hash = "e0702e2e6d1d00da65c8a29a4ebacd0a4c59e1af"
        malpedia_version = "20221125"
        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 = { 33c0 668b4702 6a00 50 }
            // n = 4, score = 800
            //   33c0                 | xor                 eax, eax
            //   668b4702             | mov                 ax, word ptr [edi + 2]
            //   6a00                 | push                0
            //   50                   | push                eax

        $sequence_1 = { 837d1000 7407 803a00 7502 eb10 47 }
            // n = 6, score = 800
            //   837d1000             | cmp                 dword ptr [ebp + 0x10], 0
            //   7407                 | je                  9
            //   803a00               | cmp                 byte ptr [edx], 0
            //   7502                 | jne                 4
            //   eb10                 | jmp                 0x12
            //   47                   | inc                 edi

        $sequence_2 = { 83c061 aa 4b 75f2 66b82e00 aa 66b86500 }
            // n = 7, score = 800
            //   83c061               | add                 eax, 0x61
            //   aa                   | stosb               byte ptr es:[edi], al
            //   4b                   | dec                 ebx
            //   75f2                 | jne                 0xfffffff4
            //   66b82e00             | mov                 ax, 0x2e
            //   aa                   | stosb               byte ptr es:[edi], al
            //   66b86500             | mov                 ax, 0x65

        $sequence_3 = { 8b450c 8945e4 c745e801000000 c745ec06000000 8d45dc 50 }
            // n = 6, score = 800
            //   8b450c               | mov                 eax, dword ptr [ebp + 0xc]
            //   8945e4               | mov                 dword ptr [ebp - 0x1c], eax
            //   c745e801000000       | mov                 dword ptr [ebp - 0x18], 1
            //   c745ec06000000       | mov                 dword ptr [ebp - 0x14], 6
            //   8d45dc               | lea                 eax, [ebp - 0x24]
            //   50                   | push                eax

        $sequence_4 = { 43 3b5dfc 7296 33c0 5e 5f }
            // n = 6, score = 800
            //   43                   | inc                 ebx
            //   3b5dfc               | cmp                 ebx, dword ptr [ebp - 4]
            //   7296                 | jb                  0xffffff98
            //   33c0                 | xor                 eax, eax
            //   5e                   | pop                 esi
            //   5f                   | pop                 edi

        $sequence_5 = { 50 8b85f4fbffff 8b10 8b520c 50 ffd2 }
            // n = 6, score = 800
            //   50                   | push                eax
            //   8b85f4fbffff         | mov                 eax, dword ptr [ebp - 0x40c]
            //   8b10                 | mov                 edx, dword ptr [eax]
            //   8b520c               | mov                 edx, dword ptr [edx + 0xc]
            //   50                   | push                eax
            //   ffd2                 | call                edx

        $sequence_6 = { 8945e4 895df4 894dec 8955fc }
            // n = 4, score = 800
            //   8945e4               | mov                 dword ptr [ebp - 0x1c], eax
            //   895df4               | mov                 dword ptr [ebp - 0xc], ebx
            //   894dec               | mov                 dword ptr [ebp - 0x14], ecx
            //   8955fc               | mov                 dword ptr [ebp - 4], edx

        $sequence_7 = { 3688b42900fcffff 3688942800fcffff fec1 75d2 }
            // n = 4, score = 800
            //   3688b42900fcffff     | mov                 byte ptr ss:[ecx + ebp - 0x400], dh
            //   3688942800fcffff     | mov                 byte ptr ss:[eax + ebp - 0x400], dl
            //   fec1                 | inc                 cl
            //   75d2                 | jne                 0xffffffd4

        $sequence_8 = { eb8e 61 c9 c20c00 55 8bec 53 }
            // n = 7, score = 800
            //   eb8e                 | jmp                 0xffffff90
            //   61                   | popal               
            //   c9                   | leave               
            //   c20c00               | ret                 0xc
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   53                   | push                ebx

        $sequence_9 = { 33c0 668b4702 50 8d4704 50 }
            // n = 5, score = 800
            //   33c0                 | xor                 eax, eax
            //   668b4702             | mov                 ax, word ptr [edi + 2]
            //   50                   | push                eax
            //   8d4704               | lea                 eax, [edi + 4]
            //   50                   | push                eax

    condition:
        7 of them and filesize < 57344
}