rule win_shimrat_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-04-08"
        version = "1"
        description = "Detects win.shimrat."
        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.shimrat"
        malpedia_rule_date = "20220405"
        malpedia_hash = "ecd38294bd47d5589be5cd5490dc8bb4804afc2a"
        malpedia_version = "20220411"
        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 = { 5e c3 0fb6c1 f7d8 ebf6 33c0 837c240420 }
            // n = 7, score = 100
            //   5e                   | pop                 esi
            //   c3                   | ret                 
            //   0fb6c1               | movzx               eax, cl
            //   f7d8                 | neg                 eax
            //   ebf6                 | jmp                 0xfffffff8
            //   33c0                 | xor                 eax, eax
            //   837c240420           | cmp                 dword ptr [esp + 4], 0x20

        $sequence_1 = { 58 c3 0fb6c0 83e008 c3 55 }
            // n = 6, score = 100
            //   58                   | pop                 eax
            //   c3                   | ret                 
            //   0fb6c0               | movzx               eax, al
            //   83e008               | and                 eax, 8
            //   c3                   | ret                 
            //   55                   | push                ebp

        $sequence_2 = { c745f801000000 395df8 0f8492feffff 895df4 395df0 0f8488000000 53 }
            // n = 7, score = 100
            //   c745f801000000       | mov                 dword ptr [ebp - 8], 1
            //   395df8               | cmp                 dword ptr [ebp - 8], ebx
            //   0f8492feffff         | je                  0xfffffe98
            //   895df4               | mov                 dword ptr [ebp - 0xc], ebx
            //   395df0               | cmp                 dword ptr [ebp - 0x10], ebx
            //   0f8488000000         | je                  0x8e
            //   53                   | push                ebx

        $sequence_3 = { 50 e8???????? 0fb745fc 32db 50 }
            // n = 5, score = 100
            //   50                   | push                eax
            //   e8????????           |                     
            //   0fb745fc             | movzx               eax, word ptr [ebp - 4]
            //   32db                 | xor                 bl, bl
            //   50                   | push                eax

        $sequence_4 = { 8d4560 50 8d4d54 e8???????? 50 8d4d54 e8???????? }
            // n = 7, score = 100
            //   8d4560               | lea                 eax, dword ptr [ebp + 0x60]
            //   50                   | push                eax
            //   8d4d54               | lea                 ecx, dword ptr [ebp + 0x54]
            //   e8????????           |                     
            //   50                   | push                eax
            //   8d4d54               | lea                 ecx, dword ptr [ebp + 0x54]
            //   e8????????           |                     

        $sequence_5 = { 53 881c30 ff15???????? 50 ff15???????? }
            // n = 5, score = 100
            //   53                   | push                ebx
            //   881c30               | mov                 byte ptr [eax + esi], bl
            //   ff15????????         |                     
            //   50                   | push                eax
            //   ff15????????         |                     

        $sequence_6 = { 8d85bcf7ffff 50 6a03 68???????? ff15???????? 8945e8 3bc3 }
            // n = 7, score = 100
            //   8d85bcf7ffff         | lea                 eax, dword ptr [ebp - 0x844]
            //   50                   | push                eax
            //   6a03                 | push                3
            //   68????????           |                     
            //   ff15????????         |                     
            //   8945e8               | mov                 dword ptr [ebp - 0x18], eax
            //   3bc3                 | cmp                 eax, ebx

        $sequence_7 = { e9???????? f6456802 8d8550ffffff 740a 68???????? e9???????? }
            // n = 6, score = 100
            //   e9????????           |                     
            //   f6456802             | test                byte ptr [ebp + 0x68], 2
            //   8d8550ffffff         | lea                 eax, dword ptr [ebp - 0xb0]
            //   740a                 | je                  0xc
            //   68????????           |                     
            //   e9????????           |                     

        $sequence_8 = { 8ad0 46 80ea41 47 80fa19 }
            // n = 5, score = 100
            //   8ad0                 | mov                 dl, al
            //   46                   | inc                 esi
            //   80ea41               | sub                 dl, 0x41
            //   47                   | inc                 edi
            //   80fa19               | cmp                 dl, 0x19

        $sequence_9 = { 56 8d85bcefffff 50 8d4d18 }
            // n = 4, score = 100
            //   56                   | push                esi
            //   8d85bcefffff         | lea                 eax, dword ptr [ebp - 0x1044]
            //   50                   | push                eax
            //   8d4d18               | lea                 ecx, dword ptr [ebp + 0x18]

    condition:
        7 of them and filesize < 65536
}