rule win_cova_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-03-28"
        version = "1"
        description = "Detects win.cova."
        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.cova"
        malpedia_rule_date = "20230328"
        malpedia_hash = "9d2d75cef573c1c2d861f5197df8f563b05a305d"
        malpedia_version = "20230407"
        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 = { 4803c7 420fb71440 8b461c 488d0c07 8b0491 }
            // n = 5, score = 100
            //   4803c7               | je                  0x8e6
            //   420fb71440           | dec                 eax
            //   8b461c               | mov                 ebx, dword ptr [esp + 0x68]
            //   488d0c07             | mov                 word ptr [ebx + 0x206], si
            //   8b0491               | test                al, al

        $sequence_1 = { ff5710 4c8d442438 448bd8 4503db 33d2 }
            // n = 5, score = 100
            //   ff5710               | dec                 eax
            //   4c8d442438           | mov                 ecx, dword ptr [eax + ecx*8]
            //   448bd8               | dec                 eax
            //   4503db               | mov                 dword ptr [esp + 8], ebx
            //   33d2                 | dec                 eax

        $sequence_2 = { 488d3d90580000 eb0e 488b03 4885c0 }
            // n = 4, score = 100
            //   488d3d90580000       | push                edi
            //   eb0e                 | dec                 eax
            //   488b03               | sub                 esp, 0x20
            //   4885c0               | dec                 eax

        $sequence_3 = { ff55c0 89442440 85c0 7407 3d80000000 751d 4c8be6 }
            // n = 7, score = 100
            //   ff55c0               | dec                 ecx
            //   89442440             | mov                 ecx, ebp
            //   85c0                 | test                eax, eax
            //   7407                 | je                  0x21d
            //   3d80000000           | inc                 ebp
            //   751d                 | xor                 ecx, ecx
            //   4c8be6               | dec                 esp

        $sequence_4 = { 4533c9 33c9 488978c8 ff9608010000 85c0 757d }
            // n = 6, score = 100
            //   4533c9               | dec                 eax
            //   33c9                 | lea                 edx, [ebp + 0x12f0]
            //   488978c8             | dec                 eax
            //   ff9608010000         | lea                 ecx, [ebp + 0x360]
            //   85c0                 | dec                 ecx
            //   757d                 | mov                 ebx, ecx

        $sequence_5 = { 49894bf0 33db 498bf1 448d4b01 498be8 ba22100000 }
            // n = 6, score = 100
            //   49894bf0             | lock dec            dword ptr [eax]
            //   33db                 | jne                 0x300
            //   498bf1               | inc                 ebx
            //   448d4b01             | xor                 cl, byte ptr [ecx + eax]
            //   498be8               | inc                 ecx
            //   ba22100000           | xor                 cl, al

        $sequence_6 = { f7e7 c1ea05 6bd264 2bfa ff9598000000 488d8b08020000 }
            // n = 6, score = 100
            //   f7e7                 | dec                 eax
            //   c1ea05               | mov                 eax, dword ptr [ebx - 0x10]
            //   6bd264               | dec                 eax
            //   2bfa                 | lea                 edi, [ebx + 0x58]
            //   ff9598000000         | mov                 esi, 6
            //   488d8b08020000       | dec                 eax

        $sequence_7 = { 4885ff 740e ff5500 4c8bc7 }
            // n = 4, score = 100
            //   4885ff               | inc                 ebp
            //   740e                 | test                ecx, ecx
            //   ff5500               | jne                 0x7b
            //   4c8bc7               | xor                 eax, 0x51e99d8

        $sequence_8 = { 0f8590000000 448af6 4d85ed 7409 }
            // n = 4, score = 100
            //   0f8590000000         | lea                 ecx, [esp + 0x58]
            //   448af6               | dec                 esp
            //   4d85ed               | lea                 eax, [esp + 0x78]
            //   7409                 | je                  0x30c

        $sequence_9 = { 4c8d4340 8d5708 488bc8 ff5650 48894500 4885c0 743b }
            // n = 7, score = 100
            //   4c8d4340             | mov                 dword ptr [ebp + 0xc], ebx
            //   8d5708               | dec                 esp
            //   488bc8               | mov                 dword ptr [ebp + 4], ebx
            //   ff5650               | rep stosd           dword ptr es:[edi], eax
            //   48894500             | dec                 eax
            //   4885c0               | lea                 edi, [0x69f2]
            //   743b                 | dec                 eax

    condition:
        7 of them and filesize < 123904
}