rule win_ranbyus_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-05-16"
        version = "1"
        description = "Detects win.ranbyus."
        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.ranbyus"
        malpedia_rule_date = "20220513"
        malpedia_hash = "7f4b2229e6ae614d86d74917f6d5b41890e62a26"
        malpedia_version = "20220516"
        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 = { 33c0 40 eb11 50 }
            // n = 4, score = 1100
            //   33c0                 | xor                 eax, eax
            //   40                   | inc                 eax
            //   eb11                 | jmp                 0x13
            //   50                   | push                eax

        $sequence_1 = { 8bc8 e8???????? 50 e8???????? 8bf0 59 }
            // n = 6, score = 1100
            //   8bc8                 | mov                 ecx, eax
            //   e8????????           |                     
            //   50                   | push                eax
            //   e8????????           |                     
            //   8bf0                 | mov                 esi, eax
            //   59                   | pop                 ecx

        $sequence_2 = { 89410b 8b4605 39780b 7407 }
            // n = 4, score = 1100
            //   89410b               | mov                 dword ptr [ecx + 0xb], eax
            //   8b4605               | mov                 eax, dword ptr [esi + 5]
            //   39780b               | cmp                 dword ptr [eax + 0xb], edi
            //   7407                 | je                  9

        $sequence_3 = { 7458 57 ff74240c 83c02c 50 e8???????? 8bf8 }
            // n = 7, score = 1100
            //   7458                 | je                  0x5a
            //   57                   | push                edi
            //   ff74240c             | push                dword ptr [esp + 0xc]
            //   83c02c               | add                 eax, 0x2c
            //   50                   | push                eax
            //   e8????????           |                     
            //   8bf8                 | mov                 edi, eax

        $sequence_4 = { ff7510 6806800000 ff7508 ff7720 }
            // n = 4, score = 1100
            //   ff7510               | push                dword ptr [ebp + 0x10]
            //   6806800000           | push                0x8006
            //   ff7508               | push                dword ptr [ebp + 8]
            //   ff7720               | push                dword ptr [edi + 0x20]

        $sequence_5 = { 8bc8 e8???????? 50 e8???????? 59 33c0 c3 }
            // n = 7, score = 1100
            //   8bc8                 | mov                 ecx, eax
            //   e8????????           |                     
            //   50                   | push                eax
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   33c0                 | xor                 eax, eax
            //   c3                   | ret                 

        $sequence_6 = { 834e2540 668b03 66894618 eb09 834e2520 8a03 884617 }
            // n = 7, score = 1100
            //   834e2540             | or                  dword ptr [esi + 0x25], 0x40
            //   668b03               | mov                 ax, word ptr [ebx]
            //   66894618             | mov                 word ptr [esi + 0x18], ax
            //   eb09                 | jmp                 0xb
            //   834e2520             | or                  dword ptr [esi + 0x25], 0x20
            //   8a03                 | mov                 al, byte ptr [ebx]
            //   884617               | mov                 byte ptr [esi + 0x17], al

        $sequence_7 = { 837d0c00 7513 68???????? ff7508 e8???????? 59 }
            // n = 6, score = 1100
            //   837d0c00             | cmp                 dword ptr [ebp + 0xc], 0
            //   7513                 | jne                 0x15
            //   68????????           |                     
            //   ff7508               | push                dword ptr [ebp + 8]
            //   e8????????           |                     
            //   59                   | pop                 ecx

        $sequence_8 = { 668b03 66894618 eb09 834e2520 8a03 884617 03d9 }
            // n = 7, score = 1100
            //   668b03               | mov                 ax, word ptr [ebx]
            //   66894618             | mov                 word ptr [esi + 0x18], ax
            //   eb09                 | jmp                 0xb
            //   834e2520             | or                  dword ptr [esi + 0x25], 0x20
            //   8a03                 | mov                 al, byte ptr [ebx]
            //   884617               | mov                 byte ptr [esi + 0x17], al
            //   03d9                 | add                 ebx, ecx

        $sequence_9 = { 84c0 0f84b9000000 46 803e45 75e3 }
            // n = 5, score = 1100
            //   84c0                 | test                al, al
            //   0f84b9000000         | je                  0xbf
            //   46                   | inc                 esi
            //   803e45               | cmp                 byte ptr [esi], 0x45
            //   75e3                 | jne                 0xffffffe5

    condition:
        7 of them and filesize < 638976
}