rule win_badcall_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-11-21"
        version = "1"
        description = "Detects win.badcall."
        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.badcall"
        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 = { a1???????? 50 c705????????04000000 ff15???????? }
            // n = 4, score = 300
            //   a1????????           |                     
            //   50                   | push                eax
            //   c705????????04000000     |     
            //   ff15????????         |                     

        $sequence_1 = { 50 e8???????? 83c404 8b7604 85f6 7409 }
            // n = 6, score = 300
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   8b7604               | mov                 esi, dword ptr [esi + 4]
            //   85f6                 | test                esi, esi
            //   7409                 | je                  0xb

        $sequence_2 = { 83c408 8d4c2410 83c618 6a04 }
            // n = 4, score = 300
            //   83c408               | add                 esp, 8
            //   8d4c2410             | lea                 ecx, [esp + 0x10]
            //   83c618               | add                 esi, 0x18
            //   6a04                 | push                4

        $sequence_3 = { 66c744241a0000 ff15???????? 8b5604 6a02 52 ff15???????? 8b4604 }
            // n = 7, score = 300
            //   66c744241a0000       | mov                 word ptr [esp + 0x1a], 0
            //   ff15????????         |                     
            //   8b5604               | mov                 edx, dword ptr [esi + 4]
            //   6a02                 | push                2
            //   52                   | push                edx
            //   ff15????????         |                     
            //   8b4604               | mov                 eax, dword ptr [esi + 4]

        $sequence_4 = { c705????????04000000 ff15???????? c20400 a1???????? 68???????? }
            // n = 5, score = 300
            //   c705????????04000000     |     
            //   ff15????????         |                     
            //   c20400               | ret                 4
            //   a1????????           |                     
            //   68????????           |                     

        $sequence_5 = { 7434 83e803 7557 33c0 }
            // n = 4, score = 300
            //   7434                 | je                  0x36
            //   83e803               | sub                 eax, 3
            //   7557                 | jne                 0x59
            //   33c0                 | xor                 eax, eax

        $sequence_6 = { c705????????01000000 a1???????? 68???????? 50 }
            // n = 4, score = 300
            //   c705????????01000000     |     
            //   a1????????           |                     
            //   68????????           |                     
            //   50                   | push                eax

        $sequence_7 = { 83c618 6a04 51 8bce e8???????? 85c0 }
            // n = 6, score = 300
            //   83c618               | add                 esi, 0x18
            //   6a04                 | push                4
            //   51                   | push                ecx
            //   8bce                 | mov                 ecx, esi
            //   e8????????           |                     
            //   85c0                 | test                eax, eax

        $sequence_8 = { 83c408 8bce 57 53 e8???????? f7d8 }
            // n = 6, score = 300
            //   83c408               | add                 esp, 8
            //   8bce                 | mov                 ecx, esi
            //   57                   | push                edi
            //   53                   | push                ebx
            //   e8????????           |                     
            //   f7d8                 | neg                 eax

        $sequence_9 = { ff15???????? c20400 c705????????01000000 a1???????? }
            // n = 4, score = 300
            //   ff15????????         |                     
            //   c20400               | ret                 4
            //   c705????????01000000     |     
            //   a1????????           |                     

        $sequence_10 = { 5f b801000000 5b 81c40c030000 c3 5f b801000000 }
            // n = 7, score = 300
            //   5f                   | pop                 edi
            //   b801000000           | mov                 eax, 1
            //   5b                   | pop                 ebx
            //   81c40c030000         | add                 esp, 0x30c
            //   c3                   | ret                 
            //   5f                   | pop                 edi
            //   b801000000           | mov                 eax, 1

        $sequence_11 = { 7557 33c0 68???????? a3???????? }
            // n = 4, score = 300
            //   7557                 | jne                 0x59
            //   33c0                 | xor                 eax, eax
            //   68????????           |                     
            //   a3????????           |                     

        $sequence_12 = { 7509 b801000000 5e c20400 8b4c2408 51 }
            // n = 6, score = 300
            //   7509                 | jne                 0xb
            //   b801000000           | mov                 eax, 1
            //   5e                   | pop                 esi
            //   c20400               | ret                 4
            //   8b4c2408             | mov                 ecx, dword ptr [esp + 8]
            //   51                   | push                ecx

        $sequence_13 = { 8d442408 6a78 8d4c2410 50 51 8b4e04 }
            // n = 6, score = 300
            //   8d442408             | lea                 eax, [esp + 8]
            //   6a78                 | push                0x78
            //   8d4c2410             | lea                 ecx, [esp + 0x10]
            //   50                   | push                eax
            //   51                   | push                ecx
            //   8b4e04               | mov                 ecx, dword ptr [esi + 4]

        $sequence_14 = { 8b442404 48 7455 48 7434 }
            // n = 5, score = 300
            //   8b442404             | mov                 eax, dword ptr [esp + 4]
            //   48                   | dec                 eax
            //   7455                 | je                  0x57
            //   48                   | dec                 eax
            //   7434                 | je                  0x36

    condition:
        7 of them and filesize < 483328
}