rule win_beatdrop_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-03-28"
        version = "1"
        description = "Detects win.beatdrop."
        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.beatdrop"
        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 = { 4883f90f 761c 488d542428 4531c0 4889d9 e8???????? }
            // n = 6, score = 400
            //   4883f90f             | mov                 eax, ebp
            //   761c                 | dec                 esp
            //   488d542428           | mov                 edx, edi
            //   4531c0               | dec                 eax
            //   4889d9               | mov                 ecx, ebx
            //   e8????????           |                     

        $sequence_1 = { c1ee10 0fb69c9800040000 400fb6f6 0fb6b4b000040000 338cb200040000 338c9a00080000 418b5b04 }
            // n = 7, score = 400
            //   c1ee10               | lea                 edx, [0x2ee4b]
            //   0fb69c9800040000     | dec                 esp
            //   400fb6f6             | mov                 ecx, ebp
            //   0fb6b4b000040000     | dec                 eax
            //   338cb200040000       | lea                 ebx, [esp + 0x2f0]
            //   338c9a00080000       | dec                 eax
            //   418b5b04             | mov                 edx, eax

        $sequence_2 = { 48894308 c6040200 4883c438 5b 5e 5f }
            // n = 6, score = 400
            //   48894308             | dec                 eax
            //   c6040200             | lea                 edx, [0x10fbd]
            //   4883c438             | dec                 esp
            //   5b                   | mov                 ecx, esi
            //   5e                   | dec                 ebp
            //   5f                   | mov                 ecx, esp

        $sequence_3 = { 4431f9 478b0c8c 47338c9c000c0000 4189d3 c1ea18 41c1eb10 44334e48 }
            // n = 7, score = 400
            //   4431f9               | mov                 eax, dword ptr [esp + 0x2c]
            //   478b0c8c             | test                eax, eax
            //   47338c9c000c0000     | jne                 0xf27
            //   4189d3               | dec                 eax
            //   c1ea18               | lea                 ecx, [0x1259d]
            //   41c1eb10             | dec                 eax
            //   44334e48             | cmp                 dword ptr [ebx + 0x20], 0

        $sequence_4 = { 4133948c00080000 89c1 440fb6c2 c1e918 0fb6ee 418b0c8c 43338c84000c0000 }
            // n = 7, score = 400
            //   4133948c00080000     | dec                 eax
            //   89c1                 | mov                 dword ptr [esi + 0x20], ebx
            //   440fb6c2             | dec                 eax
            //   c1e918               | mov                 ecx, dword ptr [esp + 0x38]
            //   0fb6ee               | dec                 eax
            //   418b0c8c             | mov                 ebx, dword ptr [ebx]
            //   43338c84000c0000     | mov                 edx, dword ptr [esp + 0x1b8]

        $sequence_5 = { 89f3 400fb6f6 c1eb10 44334d44 0fb6db 45338c9d00040000 0fb6de }
            // n = 7, score = 400
            //   89f3                 | mov                 ecx, edi
            //   400fb6f6             | dec                 eax
            //   c1eb10               | mov                 eax, dword ptr [ebx]
            //   44334d44             | mov                 dl, byte ptr [eax]
            //   0fb6db               | cmp                 dl, 1
            //   45338c9d00040000     | je                  0x1818
            //   0fb6de               | cmp                 dl, 2

        $sequence_6 = { 4489c3 450fb6c0 c1eb10 44338d84000000 }
            // n = 4, score = 400
            //   4489c3               | inc                 ecx
            //   450fb6c0             | mov                 ebx, dword ptr [ebp + ebx*4]
            //   c1eb10               | inc                 ecx
            //   44338d84000000       | xor                 ebx, dword ptr [ebp + edi*4 + 0xc00]

        $sequence_7 = { 4899 48f7f9 488d4c2428 4889442428 ff15???????? 4c89e1 4889c2 }
            // n = 7, score = 400
            //   4899                 | lea                 esi, [esp + 0x60]
            //   48f7f9               | dec                 eax
            //   488d4c2428           | lea                 edx, [0x12c7f]
            //   4889442428           | dec                 esp
            //   ff15????????         |                     
            //   4c89e1               | mov                 ecx, esi
            //   4889c2               | dec                 esp

        $sequence_8 = { 4489c8 478b749d00 c1e818 4489d1 450fb6da 418b448500 41338495000c0000 }
            // n = 7, score = 400
            //   4489c8               | call                ebx
            //   478b749d00           | dec                 eax
            //   c1e818               | lea                 ecx, [0x11ad0]
            //   4489d1               | jmp                 0x16fe
            //   450fb6da             | inc                 ecx
            //   418b448500           | mov                 eax, 0x1970
            //   41338495000c0000     | dec                 eax

        $sequence_9 = { c1e818 4533949500040000 0fb6d3 473394b500080000 }
            // n = 4, score = 400
            //   c1e818               | dec                 eax
            //   4533949500040000     | mov                 ecx, esi
            //   0fb6d3               | dec                 eax
            //   473394b500080000     | lea                 esi, [esp + 0x240]

    condition:
        7 of them and filesize < 584704
}