rule win_winmm_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.winmm."
        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.winmm"
        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 = { c3 b9???????? e9???????? b8???????? e8???????? 51 6878010000 }
            // n = 7, score = 200
            //   c3                   | ret                 
            //   b9????????           |                     
            //   e9????????           |                     
            //   b8????????           |                     
            //   e8????????           |                     
            //   51                   | push                ecx
            //   6878010000           | push                0x178

        $sequence_1 = { 81fe000c0000 7607 be000c0000 eb04 85f6 }
            // n = 5, score = 200
            //   81fe000c0000         | cmp                 esi, 0xc00
            //   7607                 | jbe                 9
            //   be000c0000           | mov                 esi, 0xc00
            //   eb04                 | jmp                 6
            //   85f6                 | test                esi, esi

        $sequence_2 = { 83e811 0f84ee000000 83e80c 0f84e5000000 48 0f84a9000000 }
            // n = 6, score = 200
            //   83e811               | sub                 eax, 0x11
            //   0f84ee000000         | je                  0xf4
            //   83e80c               | sub                 eax, 0xc
            //   0f84e5000000         | je                  0xeb
            //   48                   | dec                 eax
            //   0f84a9000000         | je                  0xaf

        $sequence_3 = { c701???????? c3 8b442404 56 8bf1 }
            // n = 5, score = 200
            //   c701????????         |                     
            //   c3                   | ret                 
            //   8b442404             | mov                 eax, dword ptr [esp + 4]
            //   56                   | push                esi
            //   8bf1                 | mov                 esi, ecx

        $sequence_4 = { 68???????? ffd7 50 e8???????? 8bf0 }
            // n = 5, score = 200
            //   68????????           |                     
            //   ffd7                 | call                edi
            //   50                   | push                eax
            //   e8????????           |                     
            //   8bf0                 | mov                 esi, eax

        $sequence_5 = { 0f84af000000 2bc1 0f849f000000 2bc1 745a }
            // n = 5, score = 200
            //   0f84af000000         | je                  0xb5
            //   2bc1                 | sub                 eax, ecx
            //   0f849f000000         | je                  0xa5
            //   2bc1                 | sub                 eax, ecx
            //   745a                 | je                  0x5c

        $sequence_6 = { c20400 ff742404 b9???????? e8???????? c3 e8???????? 8b4004 }
            // n = 7, score = 200
            //   c20400               | ret                 4
            //   ff742404             | push                dword ptr [esp + 4]
            //   b9????????           |                     
            //   e8????????           |                     
            //   c3                   | ret                 
            //   e8????????           |                     
            //   8b4004               | mov                 eax, dword ptr [eax + 4]

        $sequence_7 = { 46 8364241400 6a03 68???????? 56 e8???????? }
            // n = 6, score = 200
            //   46                   | inc                 esi
            //   8364241400           | and                 dword ptr [esp + 0x14], 0
            //   6a03                 | push                3
            //   68????????           |                     
            //   56                   | push                esi
            //   e8????????           |                     

        $sequence_8 = { 397c2428 7522 56 e8???????? 59 89442428 668b06 }
            // n = 7, score = 200
            //   397c2428             | cmp                 dword ptr [esp + 0x28], edi
            //   7522                 | jne                 0x24
            //   56                   | push                esi
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   89442428             | mov                 dword ptr [esp + 0x28], eax
            //   668b06               | mov                 ax, word ptr [esi]

        $sequence_9 = { 7c02 8bfd 3b7c2428 7f5a 8b7c2428 }
            // n = 5, score = 200
            //   7c02                 | jl                  4
            //   8bfd                 | mov                 edi, ebp
            //   3b7c2428             | cmp                 edi, dword ptr [esp + 0x28]
            //   7f5a                 | jg                  0x5c
            //   8b7c2428             | mov                 edi, dword ptr [esp + 0x28]

    condition:
        7 of them and filesize < 278528
}