rule win_rapid_ransom_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-11-21"
        version = "1"
        description = "Detects win.rapid_ransom."
        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.rapid_ransom"
        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 = { 50 6801000004 6800a40000 ff75f8 }
            // n = 4, score = 300
            //   50                   | push                eax
            //   6801000004           | push                0x4000001
            //   6800a40000           | push                0xa400
            //   ff75f8               | push                dword ptr [ebp - 8]

        $sequence_1 = { 897c243c e8???????? 83c410 84c0 0f94c1 }
            // n = 5, score = 200
            //   897c243c             | mov                 dword ptr [esp + 0x3c], edi
            //   e8????????           |                     
            //   83c410               | add                 esp, 0x10
            //   84c0                 | test                al, al
            //   0f94c1               | sete                cl

        $sequence_2 = { ff75fc 51 6801000040 ff750c 53 }
            // n = 5, score = 200
            //   ff75fc               | push                dword ptr [ebp - 4]
            //   51                   | push                ecx
            //   6801000040           | push                0x40000001
            //   ff750c               | push                dword ptr [ebp + 0xc]
            //   53                   | push                ebx

        $sequence_3 = { 32c0 8844240f 33c0 c644240e00 }
            // n = 4, score = 200
            //   32c0                 | xor                 al, al
            //   8844240f             | mov                 byte ptr [esp + 0xf], al
            //   33c0                 | xor                 eax, eax
            //   c644240e00           | mov                 byte ptr [esp + 0xe], 0

        $sequence_4 = { 8bf9 32db 8bf2 85ff 0f849c000000 85f6 0f8494000000 }
            // n = 7, score = 200
            //   8bf9                 | mov                 edi, ecx
            //   32db                 | xor                 bl, bl
            //   8bf2                 | mov                 esi, edx
            //   85ff                 | test                edi, edi
            //   0f849c000000         | je                  0xa2
            //   85f6                 | test                esi, esi
            //   0f8494000000         | je                  0x9a

        $sequence_5 = { 0f84dd000000 8b442420 8b5c2410 85442438 0f84cf000000 }
            // n = 5, score = 200
            //   0f84dd000000         | je                  0xe3
            //   8b442420             | mov                 eax, dword ptr [esp + 0x20]
            //   8b5c2410             | mov                 ebx, dword ptr [esp + 0x10]
            //   85442438             | test                dword ptr [esp + 0x38], eax
            //   0f84cf000000         | je                  0xd5

        $sequence_6 = { 7447 8d45f4 c745f494000000 50 57 }
            // n = 5, score = 200
            //   7447                 | je                  0x49
            //   8d45f4               | lea                 eax, [ebp - 0xc]
            //   c745f494000000       | mov                 dword ptr [ebp - 0xc], 0x94
            //   50                   | push                eax
            //   57                   | push                edi

        $sequence_7 = { 8d442440 56 50 ff5514 8b4c2448 83c410 8a44240e }
            // n = 7, score = 200
            //   8d442440             | lea                 eax, [esp + 0x40]
            //   56                   | push                esi
            //   50                   | push                eax
            //   ff5514               | call                dword ptr [ebp + 0x14]
            //   8b4c2448             | mov                 ecx, dword ptr [esp + 0x48]
            //   83c410               | add                 esp, 0x10
            //   8a44240e             | mov                 al, byte ptr [esp + 0xe]

        $sequence_8 = { 83c9ff c7430c01000000 c7431000000000 eb2f 8b45f8 }
            // n = 5, score = 100
            //   83c9ff               | or                  ecx, 0xffffffff
            //   c7430c01000000       | mov                 dword ptr [ebx + 0xc], 1
            //   c7431000000000       | mov                 dword ptr [ebx + 0x10], 0
            //   eb2f                 | jmp                 0x31
            //   8b45f8               | mov                 eax, dword ptr [ebp - 8]

        $sequence_9 = { 0f57c0 57 660fd645e8 ffd6 }
            // n = 4, score = 100
            //   0f57c0               | xorps               xmm0, xmm0
            //   57                   | push                edi
            //   660fd645e8           | movq                qword ptr [ebp - 0x18], xmm0
            //   ffd6                 | call                esi

        $sequence_10 = { 68ff000000 53 6a01 50 68???????? }
            // n = 5, score = 100
            //   68ff000000           | push                0xff
            //   53                   | push                ebx
            //   6a01                 | push                1
            //   50                   | push                eax
            //   68????????           |                     

        $sequence_11 = { 8b55b4 8bd8 8b4dd4 e8???????? 8b4dd4 }
            // n = 5, score = 100
            //   8b55b4               | mov                 edx, dword ptr [ebp - 0x4c]
            //   8bd8                 | mov                 ebx, eax
            //   8b4dd4               | mov                 ecx, dword ptr [ebp - 0x2c]
            //   e8????????           |                     
            //   8b4dd4               | mov                 ecx, dword ptr [ebp - 0x2c]

        $sequence_12 = { 740b 46 81fe00010000 72a7 eb03 8975cc 8b75c4 }
            // n = 7, score = 100
            //   740b                 | je                  0xd
            //   46                   | inc                 esi
            //   81fe00010000         | cmp                 esi, 0x100
            //   72a7                 | jb                  0xffffffa9
            //   eb03                 | jmp                 5
            //   8975cc               | mov                 dword ptr [ebp - 0x34], esi
            //   8b75c4               | mov                 esi, dword ptr [ebp - 0x3c]

        $sequence_13 = { 6a01 6810660000 ff75ec ff15???????? 85c0 0f8430040000 }
            // n = 6, score = 100
            //   6a01                 | push                1
            //   6810660000           | push                0x6610
            //   ff75ec               | push                dword ptr [ebp - 0x14]
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   0f8430040000         | je                  0x436

        $sequence_14 = { c745d000000000 33f6 3803 7407 40 803c0300 75f9 }
            // n = 7, score = 100
            //   c745d000000000       | mov                 dword ptr [ebp - 0x30], 0
            //   33f6                 | xor                 esi, esi
            //   3803                 | cmp                 byte ptr [ebx], al
            //   7407                 | je                  9
            //   40                   | inc                 eax
            //   803c0300             | cmp                 byte ptr [ebx + eax], 0
            //   75f9                 | jne                 0xfffffffb

    condition:
        7 of them and filesize < 286720
}