恶意代码的yara规则

malware.yar

rule win_gaudox_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2018-11-23"
        version = "1"
        description = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator 0.1a"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.gaudox"
        malpedia_version = "20180607"
        malpedia_license = "CC BY-NC-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 / approach will be published in the near future 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 = { 50 51 6a0b 6a01 }
            // n = 4, score = 1000
            //   50                   | push                eax
            //   51                   | push                ecx
            //   6a0b                 | push                0xb
            //   6a01                 | push                1

        $sequence_1 = { 03c6 50 56 e8051d0000 }
            // n = 4, score = 1000
            //   03c6                 | add                 eax, esi
            //   50                   | push                eax
            //   56                   | push                esi
            //   e8051d0000           | call                0x93220

        $sequence_2 = { 2bd7 742c 8b45fc 8a11 }
            // n = 4, score = 1000
            //   2bd7                 | sub                 edx, edi
            //   742c                 | je                  0x93319
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   8a11                 | mov                 dl, byte ptr [ecx]

        $sequence_3 = { 50 6a40 8d45fc 895df8 }
            // n = 4, score = 1000
            //   50                   | push                eax
            //   6a40                 | push                0x40
            //   8d45fc               | lea                 eax, dword ptr [ebp - 4]
            //   895df8               | mov                 dword ptr [ebp - 8], ebx

        $sequence_4 = { 48 740a 48 757e }
            // n = 4, score = 1000
            //   48                   | dec                 eax
            //   740a                 | je                  0x98128
            //   48                   | dec                 eax
            //   757e                 | jne                 0x9819f

        $sequence_5 = { 33c0 c6450b00 0f57c0 f30f7f06 }
            // n = 4, score = 1000
            //   33c0                 | xor                 eax, eax
            //   c6450b00             | mov                 byte ptr [ebp + 0xb], 0
            //   0f57c0               | xorps               xmm0, xmm0
            //   f30f7f06             | movdqu              xmmword ptr [esi], xmm0

        $sequence_6 = { 0fb755e6 83fa5a 7f0c 0fb745e6 }
            // n = 4, score = 1000
            //   0fb755e6             | movzx               edx, word ptr [ebp - 0x1a]
            //   83fa5a               | cmp                 edx, 0x5a
            //   7f0c                 | jg                  0x95fff
            //   0fb745e6             | movzx               eax, word ptr [ebp - 0x1a]

        $sequence_7 = { 4f 75f3 8b4dfc 85f6 }
            // n = 4, score = 1000
            //   4f                   | dec                 edi
            //   75f3                 | jne                 0x93183
            //   8b4dfc               | mov                 ecx, dword ptr [ebp - 4]
            //   85f6                 | test                esi, esi

        $sequence_8 = { 52 8b45dc 50 8d55f0 }
            // n = 4, score = 1000
            //   52                   | push                edx
            //   8b45dc               | mov                 eax, dword ptr [ebp - 0x24]
            //   50                   | push                eax
            //   8d55f0               | lea                 edx, dword ptr [ebp - 0x10]

        $sequence_9 = { 51 8d8114010000 50 e81786ffff }
            // n = 4, score = 1000
            //   51                   | push                ecx
            //   8d8114010000         | lea                 eax, dword ptr [ecx + 0x114]
            //   50                   | push                eax
            //   e81786ffff           | call                0x91890

    condition:
        7 of them
}