rule win_compfun_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.compfun."
        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.compfun"
        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 = { c746086b656e50 c7460c72697669 c746106c656765 c6461500 8bc6 5e 5d }
            // n = 7, score = 300
            //   c746086b656e50       | mov                 dword ptr [esi + 8], 0x506e656b
            //   c7460c72697669       | mov                 dword ptr [esi + 0xc], 0x69766972
            //   c746106c656765       | mov                 dword ptr [esi + 0x10], 0x6567656c
            //   c6461500             | mov                 byte ptr [esi + 0x15], 0
            //   8bc6                 | mov                 eax, esi
            //   5e                   | pop                 esi
            //   5d                   | pop                 ebp

        $sequence_1 = { 6880000000 6a00 56 e8???????? 83c40c c70652656164 c7460446696c65 }
            // n = 7, score = 300
            //   6880000000           | push                0x80
            //   6a00                 | push                0
            //   56                   | push                esi
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   c70652656164         | mov                 dword ptr [esi], 0x64616552
            //   c7460446696c65       | mov                 dword ptr [esi + 4], 0x656c6946

        $sequence_2 = { c7460465745661 c746086c756545 c6460e00 8bc6 5e }
            // n = 5, score = 300
            //   c7460465745661       | mov                 dword ptr [esi + 4], 0x61567465
            //   c746086c756545       | mov                 dword ptr [esi + 8], 0x4565756c
            //   c6460e00             | mov                 byte ptr [esi + 0xe], 0
            //   8bc6                 | mov                 eax, esi
            //   5e                   | pop                 esi

        $sequence_3 = { c74614696e6773 c6461900 8bc6 5e }
            // n = 4, score = 300
            //   c74614696e6773       | mov                 dword ptr [esi + 0x14], 0x73676e69
            //   c6461900             | mov                 byte ptr [esi + 0x19], 0
            //   8bc6                 | mov                 eax, esi
            //   5e                   | pop                 esi

        $sequence_4 = { 83c40c c7461445785720 c7064b333247 c7460465744d6f c7460864756c65 c7460c46696c65 }
            // n = 6, score = 300
            //   83c40c               | add                 esp, 0xc
            //   c7461445785720       | mov                 dword ptr [esi + 0x14], 0x20577845
            //   c7064b333247         | mov                 dword ptr [esi], 0x4732334b
            //   c7460465744d6f       | mov                 dword ptr [esi + 4], 0x6f4d7465
            //   c7460864756c65       | mov                 dword ptr [esi + 8], 0x656c7564
            //   c7460c46696c65       | mov                 dword ptr [esi + 0xc], 0x656c6946

        $sequence_5 = { 8d45f0 50 6a00 50 }
            // n = 4, score = 300
            //   8d45f0               | lea                 eax, [ebp - 0x10]
            //   50                   | push                eax
            //   6a00                 | push                0
            //   50                   | push                eax

        $sequence_6 = { c7460474655265 c746086d6f7465 c7460c54687265 c6461200 8bc6 5e }
            // n = 6, score = 300
            //   c7460474655265       | mov                 dword ptr [esi + 4], 0x65526574
            //   c746086d6f7465       | mov                 dword ptr [esi + 8], 0x65746f6d
            //   c7460c54687265       | mov                 dword ptr [esi + 0xc], 0x65726854
            //   c6461200             | mov                 byte ptr [esi + 0x12], 0
            //   8bc6                 | mov                 eax, esi
            //   5e                   | pop                 esi

        $sequence_7 = { 83c40c c74608646c6520 c706436c6f73 c746046548616e c6460b00 8bc6 }
            // n = 6, score = 300
            //   83c40c               | add                 esp, 0xc
            //   c74608646c6520       | mov                 dword ptr [esi + 8], 0x20656c64
            //   c706436c6f73         | mov                 dword ptr [esi], 0x736f6c43
            //   c746046548616e       | mov                 dword ptr [esi + 4], 0x6e614865
            //   c6460b00             | mov                 byte ptr [esi + 0xb], 0
            //   8bc6                 | mov                 eax, esi

        $sequence_8 = { 034c2460 488b442450 894820 488b4c2450 }
            // n = 4, score = 100
            //   034c2460             | lea                 edx, [esp + 0x40]
            //   488b442450           | dec                 eax
            //   894820               | mov                 ecx, dword ptr [esp + 0x70]
            //   488b4c2450           | add                 ecx, dword ptr [esp + 0x2c]

        $sequence_9 = { 03c1 89442420 8b542438 486bd218 }
            // n = 4, score = 100
            //   03c1                 | movzx               eax, byte ptr [eax + eax]
            //   89442420             | mov                 byte ptr [ecx + edx], al
            //   8b542438             | mov                 eax, dword ptr [esp + 0x18]
            //   486bd218             | add                 eax, ecx

        $sequence_10 = { 034c242c 488b442470 894820 488d542440 }
            // n = 4, score = 100
            //   034c242c             | add                 eax, dword ptr [esp + 0x2c]
            //   488b442470           | mov                 ecx, eax
            //   894820               | dec                 eax
            //   488d542440           | mov                 dword ptr [esp + 0x48], eax

        $sequence_11 = { 03c1 89442420 8b442420 83c001 }
            // n = 4, score = 100
            //   03c1                 | add                 ecx, dword ptr [esp + 0x60]
            //   89442420             | dec                 eax
            //   8b442420             | mov                 eax, dword ptr [esp + 0x50]
            //   83c001               | mov                 dword ptr [eax + 0x20], ecx

        $sequence_12 = { 03c1 89442420 8b4c2438 488b442450 }
            // n = 4, score = 100
            //   03c1                 | dec                 eax
            //   89442420             | mov                 eax, dword ptr [esp + 0x38]
            //   8b4c2438             | inc                 edx
            //   488b442450           | movzx               eax, byte ptr [eax + eax]

        $sequence_13 = { 03c1 4863d0 488b4c2430 488b442438 }
            // n = 4, score = 100
            //   03c1                 | add                 ecx, dword ptr [esp + 0x60]
            //   4863d0               | dec                 eax
            //   488b4c2430           | mov                 eax, dword ptr [esp + 0x50]
            //   488b442438           | mov                 dword ptr [eax + 0x20], ecx

        $sequence_14 = { 03c1 89442434 8b442430 39442434 }
            // n = 4, score = 100
            //   03c1                 | mov                 dword ptr [esp + 0x20], eax
            //   89442434             | mov                 eax, dword ptr [esp + 0x20]
            //   8b442430             | add                 eax, 0xa
            //   39442434             | add                 eax, ecx

        $sequence_15 = { 0344242c 8bc8 e8???????? 4889442448 }
            // n = 4, score = 100
            //   0344242c             | add                 eax, dword ptr [esp + 0x2c]
            //   8bc8                 | mov                 ecx, eax
            //   e8????????           |                     
            //   4889442448           | dec                 eax

    condition:
        7 of them and filesize < 402432
}