rule win_virut_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.virut."
        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.virut"
        malpedia_rule_date = "20230705"
        malpedia_hash = "42d0574f4405bd7d2b154d321d345acb18834a41"
        malpedia_version = "20230715"
        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 ff15???????? 8bf0 3bf3 0f8e82000000 ff74240c 57 }
            // n = 7, score = 200
            //   50                   | push                eax
            //   ff15????????         |                     
            //   8bf0                 | mov                 esi, eax
            //   3bf3                 | cmp                 esi, ebx
            //   0f8e82000000         | jle                 0x88
            //   ff74240c             | push                dword ptr [esp + 0xc]
            //   57                   | push                edi

        $sequence_1 = { 50 54 50 56 51 }
            // n = 5, score = 200
            //   50                   | push                eax
            //   54                   | push                esp
            //   50                   | push                eax
            //   56                   | push                esi
            //   51                   | push                ecx

        $sequence_2 = { 6a10 59 f3ab 50 50 50 }
            // n = 6, score = 200
            //   6a10                 | push                0x10
            //   59                   | pop                 ecx
            //   f3ab                 | rep stosd           dword ptr es:[edi], eax
            //   50                   | push                eax
            //   50                   | push                eax
            //   50                   | push                eax

        $sequence_3 = { 57 56 ff15???????? 56 ff15???????? 6a44 }
            // n = 6, score = 200
            //   57                   | push                edi
            //   56                   | push                esi
            //   ff15????????         |                     
            //   56                   | push                esi
            //   ff15????????         |                     
            //   6a44                 | push                0x44

        $sequence_4 = { 8bcf 52 f6d9 52 83e103 }
            // n = 5, score = 200
            //   8bcf                 | mov                 ecx, edi
            //   52                   | push                edx
            //   f6d9                 | neg                 cl
            //   52                   | push                edx
            //   83e103               | and                 ecx, 3

        $sequence_5 = { 69c06d4ec641 0539300000 a3???????? c1e80a c3 55 8bec }
            // n = 7, score = 200
            //   69c06d4ec641         | imul                eax, eax, 0x41c64e6d
            //   0539300000           | add                 eax, 0x3039
            //   a3????????           |                     
            //   c1e80a               | shr                 eax, 0xa
            //   c3                   | ret                 
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp

        $sequence_6 = { 7416 e314 50 8bd4 6a00 }
            // n = 5, score = 200
            //   7416                 | je                  0x18
            //   e314                 | jecxz               0x16
            //   50                   | push                eax
            //   8bd4                 | mov                 edx, esp
            //   6a00                 | push                0

        $sequence_7 = { 50 53 6a05 8bcc }
            // n = 4, score = 200
            //   50                   | push                eax
            //   53                   | push                ebx
            //   6a05                 | push                5
            //   8bcc                 | mov                 ecx, esp

        $sequence_8 = { 74c7 885c2413 ff742418 ff15???????? 385c2413 0f8402010000 803f4d }
            // n = 7, score = 200
            //   74c7                 | je                  0xffffffc9
            //   885c2413             | mov                 byte ptr [esp + 0x13], bl
            //   ff742418             | push                dword ptr [esp + 0x18]
            //   ff15????????         |                     
            //   385c2413             | cmp                 byte ptr [esp + 0x13], bl
            //   0f8402010000         | je                  0x108
            //   803f4d               | cmp                 byte ptr [edi], 0x4d

        $sequence_9 = { 2bcb 60 8bcb f3a6 61 }
            // n = 5, score = 200
            //   2bcb                 | sub                 ecx, ebx
            //   60                   | pushal              
            //   8bcb                 | mov                 ecx, ebx
            //   f3a6                 | repe cmpsb          byte ptr [esi], byte ptr es:[edi]
            //   61                   | popal               

        $sequence_10 = { 50 ff15???????? 6800100000 8d842474050000 50 8d8424d0000000 50 }
            // n = 7, score = 200
            //   50                   | push                eax
            //   ff15????????         |                     
            //   6800100000           | push                0x1000
            //   8d842474050000       | lea                 eax, [esp + 0x574]
            //   50                   | push                eax
            //   8d8424d0000000       | lea                 eax, [esp + 0xd0]
            //   50                   | push                eax

        $sequence_11 = { 885c2422 885c2423 33c9 e8???????? }
            // n = 4, score = 200
            //   885c2422             | mov                 byte ptr [esp + 0x22], bl
            //   885c2423             | mov                 byte ptr [esp + 0x23], bl
            //   33c9                 | xor                 ecx, ecx
            //   e8????????           |                     

        $sequence_12 = { 46 3bf1 7ce5 8b442414 6a03 99 }
            // n = 6, score = 200
            //   46                   | inc                 esi
            //   3bf1                 | cmp                 esi, ecx
            //   7ce5                 | jl                  0xffffffe7
            //   8b442414             | mov                 eax, dword ptr [esp + 0x14]
            //   6a03                 | push                3
            //   99                   | cdq                 

        $sequence_13 = { 8d8424d4010000 50 56 e8???????? 83c40c }
            // n = 5, score = 200
            //   8d8424d4010000       | lea                 eax, [esp + 0x1d4]
            //   50                   | push                eax
            //   56                   | push                esi
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc

        $sequence_14 = { 8bc4 6a00 6800000008 6a40 51 52 }
            // n = 6, score = 200
            //   8bc4                 | mov                 eax, esp
            //   6a00                 | push                0
            //   6800000008           | push                0x8000000
            //   6a40                 | push                0x40
            //   51                   | push                ecx
            //   52                   | push                edx

        $sequence_15 = { 43 4b 3332 2e44 4c }
            // n = 5, score = 200
            //   43                   | inc                 ebx
            //   4b                   | dec                 ebx
            //   3332                 | xor                 esi, dword ptr [edx]
            //   2e44                 | inc                 esp
            //   4c                   | dec                 esp

    condition:
        7 of them and filesize < 98304
}