rule win_badcall_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2020-05-30"
        version = "1"
        description = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.4.0"
        tool_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.badcall"
        malpedia_rule_date = "20200529"
        malpedia_hash = "92c362319514e5a6da26204961446caa3a8b32a8"
        malpedia_version = "20200529"
        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 / approach 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 = { aa b940000000 33c0 8d7c2411 895c2408 f3ab }
            // n = 6, score = 300
            //   aa                   | stosb               byte ptr es:[edi], al
            //   b940000000           | mov                 ecx, 0x40
            //   33c0                 | xor                 eax, eax
            //   8d7c2411             | lea                 edi, [esp + 0x11]
            //   895c2408             | mov                 dword ptr [esp + 8], ebx
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax

        $sequence_1 = { 8bf1 e8???????? 8b442408 894610 e8???????? }
            // n = 5, score = 300
            //   8bf1                 | mov                 esi, ecx
            //   e8????????           |                     
            //   8b442408             | mov                 eax, dword ptr [esp + 8]
            //   894610               | mov                 dword ptr [esi + 0x10], eax
            //   e8????????           |                     

        $sequence_2 = { f7d1 49 be???????? 8bc1 8bd1 }
            // n = 5, score = 300
            //   f7d1                 | not                 ecx
            //   49                   | dec                 ecx
            //   be????????           |                     
            //   8bc1                 | mov                 eax, ecx
            //   8bd1                 | mov                 edx, ecx

        $sequence_3 = { 7615 8a4c2408 8a542420 3aca }
            // n = 4, score = 300
            //   7615                 | jbe                 0x17
            //   8a4c2408             | mov                 cl, byte ptr [esp + 8]
            //   8a542420             | mov                 dl, byte ptr [esp + 0x20]
            //   3aca                 | cmp                 cl, dl

        $sequence_4 = { 8b442404 48 7455 48 }
            // n = 4, score = 300
            //   8b442404             | mov                 eax, dword ptr [esp + 4]
            //   48                   | dec                 eax
            //   7455                 | je                  0x57
            //   48                   | dec                 eax

        $sequence_5 = { 7455 48 7434 83e803 7557 }
            // n = 5, score = 300
            //   7455                 | je                  0x57
            //   48                   | dec                 eax
            //   7434                 | je                  0x36
            //   83e803               | sub                 eax, 3
            //   7557                 | jne                 0x59

        $sequence_6 = { 7557 33c0 68???????? a3???????? a3???????? }
            // n = 5, score = 300
            //   7557                 | jne                 0x59
            //   33c0                 | xor                 eax, eax
            //   68????????           |                     
            //   a3????????           |                     
            //   a3????????           |                     

        $sequence_7 = { a1???????? 50 c705????????04000000 ff15???????? c20400 }
            // n = 5, score = 300
            //   a1????????           |                     
            //   50                   | push                eax
            //   c705????????04000000     |     
            //   ff15????????         |                     
            //   c20400               | ret                 4

        $sequence_8 = { ff15???????? c20400 c705????????01000000 a1???????? }
            // n = 4, score = 300
            //   ff15????????         |                     
            //   c20400               | ret                 4
            //   c705????????01000000     |     
            //   a1????????           |                     

        $sequence_9 = { 8b5604 8d4c2408 6a10 51 }
            // n = 4, score = 300
            //   8b5604               | mov                 edx, dword ptr [esi + 4]
            //   8d4c2408             | lea                 ecx, [esp + 8]
            //   6a10                 | push                0x10
            //   51                   | push                ecx

        $sequence_10 = { ff15???????? c20400 a1???????? 68???????? 50 }
            // n = 5, score = 300
            //   ff15????????         |                     
            //   c20400               | ret                 4
            //   a1????????           |                     
            //   68????????           |                     
            //   50                   | push                eax

        $sequence_11 = { 8bf0 83feff 7450 6a14 6a40 }
            // n = 5, score = 300
            //   8bf0                 | mov                 esi, eax
            //   83feff               | cmp                 esi, -1
            //   7450                 | je                  0x52
            //   6a14                 | push                0x14
            //   6a40                 | push                0x40

        $sequence_12 = { 6a32 ffd7 eb87 8d4c2424 e8???????? }
            // n = 5, score = 300
            //   6a32                 | push                0x32
            //   ffd7                 | call                edi
            //   eb87                 | jmp                 0xffffff89
            //   8d4c2424             | lea                 ecx, [esp + 0x24]
            //   e8????????           |                     

        $sequence_13 = { 83f8ff 740d 5f b801000000 }
            // n = 4, score = 300
            //   83f8ff               | cmp                 eax, -1
            //   740d                 | je                  0xf
            //   5f                   | pop                 edi
            //   b801000000           | mov                 eax, 1

        $sequence_14 = { 89563c 89777c 5f 5e }
            // n = 4, score = 200
            //   89563c               | mov                 dword ptr [esi + 0x3c], edx
            //   89777c               | mov                 dword ptr [edi + 0x7c], esi
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi

        $sequence_15 = { 8b5628 51 52 ff5624 8b442420 83c408 }
            // n = 6, score = 200
            //   8b5628               | mov                 edx, dword ptr [esi + 0x28]
            //   51                   | push                ecx
            //   52                   | push                edx
            //   ff5624               | call                dword ptr [esi + 0x24]
            //   8b442420             | mov                 eax, dword ptr [esp + 0x20]
            //   83c408               | add                 esp, 8

    condition:
        7 of them and filesize < 483328
}