rule win_systembc_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        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 = "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 = { 4f 75cc 33c0 8dbd00fcffff }
            // n = 4, score = 800
            //   4f                   | dec                 edi
            //   75cc                 | jne                 0xffffffce
            //   33c0                 | xor                 eax, eax
            //   8dbd00fcffff         | lea                 edi, [ebp - 0x400]

        $sequence_1 = { 8b4c307c 8955ec 894de8 0bc0 0f8495000000 8d0432 }
            // n = 6, score = 800
            //   8b4c307c             | mov                 ecx, dword ptr [eax + esi + 0x7c]
            //   8955ec               | mov                 dword ptr [ebp - 0x14], edx
            //   894de8               | mov                 dword ptr [ebp - 0x18], ecx
            //   0bc0                 | or                  eax, eax
            //   0f8495000000         | je                  0x9b
            //   8d0432               | lea                 eax, [edx + esi]

        $sequence_2 = { 668b9554f9ffff 6a00 6a00 6a03 6a00 6a00 }
            // n = 6, score = 800
            //   668b9554f9ffff       | mov                 dx, word ptr [ebp - 0x6ac]
            //   6a00                 | push                0
            //   6a00                 | push                0
            //   6a03                 | push                3
            //   6a00                 | push                0
            //   6a00                 | push                0

        $sequence_3 = { 898538f4ffff 8bbd4cf9ffff 8b8d50f9ffff c6043900 33d2 }
            // n = 5, score = 800
            //   898538f4ffff         | mov                 dword ptr [ebp - 0xbc8], eax
            //   8bbd4cf9ffff         | mov                 edi, dword ptr [ebp - 0x6b4]
            //   8b8d50f9ffff         | mov                 ecx, dword ptr [ebp - 0x6b0]
            //   c6043900             | mov                 byte ptr [ecx + edi], 0
            //   33d2                 | xor                 edx, edx

        $sequence_4 = { 50 6aff ff75d8 e8???????? 8d85d8fdffff 50 }
            // n = 6, score = 800
            //   50                   | push                eax
            //   6aff                 | push                -1
            //   ff75d8               | push                dword ptr [ebp - 0x28]
            //   e8????????           |                     
            //   8d85d8fdffff         | lea                 eax, [ebp - 0x228]
            //   50                   | push                eax

        $sequence_5 = { 50 6805000020 ffb530f4ffff 68???????? e8???????? }
            // n = 5, score = 800
            //   50                   | push                eax
            //   6805000020           | push                0x20000005
            //   ffb530f4ffff         | push                dword ptr [ebp - 0xbd0]
            //   68????????           |                     
            //   e8????????           |                     

        $sequence_6 = { eb02 3007 49 837d0cfe 751c }
            // n = 5, score = 800
            //   eb02                 | jmp                 4
            //   3007                 | xor                 byte ptr [edi], al
            //   49                   | dec                 ecx
            //   837d0cfe             | cmp                 dword ptr [ebp + 0xc], -2
            //   751c                 | jne                 0x1e

        $sequence_7 = { 8b4de8 03d6 03c6 03ca 3bc2 762f 3bc1 }
            // n = 7, score = 800
            //   8b4de8               | mov                 ecx, dword ptr [ebp - 0x18]
            //   03d6                 | add                 edx, esi
            //   03c6                 | add                 eax, esi
            //   03ca                 | add                 ecx, edx
            //   3bc2                 | cmp                 eax, edx
            //   762f                 | jbe                 0x31
            //   3bc1                 | cmp                 eax, ecx

        $sequence_8 = { 8d851cf4ffff 50 6800010000 57 ffb530f4ffff }
            // n = 5, score = 800
            //   8d851cf4ffff         | lea                 eax, [ebp - 0xbe4]
            //   50                   | push                eax
            //   6800010000           | push                0x100
            //   57                   | push                edi
            //   ffb530f4ffff         | push                dword ptr [ebp - 0xbd0]

        $sequence_9 = { 8945fc c785f4feffff00000000 8d85f4feffff 50 8d45f8 }
            // n = 5, score = 800
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   c785f4feffff00000000     | mov    dword ptr [ebp - 0x10c], 0
            //   8d85f4feffff         | lea                 eax, [ebp - 0x10c]
            //   50                   | push                eax
            //   8d45f8               | lea                 eax, [ebp - 8]

    condition:
        7 of them and filesize < 57344
}