rule win_tinyloader_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2020-10-14"
        version = "1"
        description = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.5.0"
        tool_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.tinyloader"
        malpedia_rule_date = "20201014"
        malpedia_hash = "a7e3bd57eaf12bf3ea29a863c041091ba3af9ac9"
        malpedia_version = "20201014"
        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 = { 8b5d00 039d58080000 6a00 6800040000 }
            // n = 4, score = 100
            //   8b5d00               | mov                 ebx, dword ptr [ebp]
            //   039d58080000         | add                 ebx, dword ptr [ebp + 0x858]
            //   6a00                 | push                0
            //   6800040000           | push                0x400

        $sequence_1 = { 637574 6541 0050ff 15???????? c705????????00010000 }
            // n = 5, score = 100
            //   637574               | arpl                word ptr [ebp + 0x74], si
            //   6541                 | inc                 ecx
            //   0050ff               | add                 byte ptr [eax - 1], dl
            //   15????????           |                     
            //   c705????????00010000     |     

        $sequence_2 = { 7405 83f800 7505 e9???????? 018558080000 }
            // n = 5, score = 100
            //   7405                 | je                  7
            //   83f800               | cmp                 eax, 0
            //   7505                 | jne                 7
            //   e9????????           |                     
            //   018558080000         | add                 dword ptr [ebp + 0x858], eax

        $sequence_3 = { c783000400000c000000 8b8540050000 8b5d00 894308 8b85f8070000 8b5d00 894304 }
            // n = 7, score = 100
            //   c783000400000c000000     | mov    dword ptr [ebx + 0x400], 0xc
            //   8b8540050000         | mov                 eax, dword ptr [ebp + 0x540]
            //   8b5d00               | mov                 ebx, dword ptr [ebp]
            //   894308               | mov                 dword ptr [ebx + 8], eax
            //   8b85f8070000         | mov                 eax, dword ptr [ebp + 0x7f8]
            //   8b5d00               | mov                 ebx, dword ptr [ebp]
            //   894304               | mov                 dword ptr [ebx + 4], eax

        $sequence_4 = { 81fb04030000 730c 90 83c004 90 }
            // n = 5, score = 100
            //   81fb04030000         | cmp                 ebx, 0x304
            //   730c                 | jae                 0xe
            //   90                   | nop                 
            //   83c004               | add                 eax, 4
            //   90                   | nop                 

        $sequence_5 = { 894518 0500200000 894510 0500080000 894520 ffb5a0050000 }
            // n = 6, score = 100
            //   894518               | mov                 dword ptr [ebp + 0x18], eax
            //   0500200000           | add                 eax, 0x2000
            //   894510               | mov                 dword ptr [ebp + 0x10], eax
            //   0500080000           | add                 eax, 0x800
            //   894520               | mov                 dword ptr [ebp + 0x20], eax
            //   ffb5a0050000         | push                dword ptr [ebp + 0x5a0]

        $sequence_6 = { 8b5d00 8b4308 83f800 7407 807c03ffc3 7402 }
            // n = 6, score = 100
            //   8b5d00               | mov                 ebx, dword ptr [ebp]
            //   8b4308               | mov                 eax, dword ptr [ebx + 8]
            //   83f800               | cmp                 eax, 0
            //   7407                 | je                  9
            //   807c03ffc3           | cmp                 byte ptr [ebx + eax - 1], 0xc3
            //   7402                 | je                  4

        $sequence_7 = { 83c00c ffd0 31db 8b4500 8b8000040000 }
            // n = 5, score = 100
            //   83c00c               | add                 eax, 0xc
            //   ffd0                 | call                eax
            //   31db                 | xor                 ebx, ebx
            //   8b4500               | mov                 eax, dword ptr [ebp]
            //   8b8000040000         | mov                 eax, dword ptr [eax + 0x400]

        $sequence_8 = { 8938 90 81fb04030000 730d }
            // n = 4, score = 100
            //   8938                 | mov                 dword ptr [eax], edi
            //   90                   | nop                 
            //   81fb04030000         | cmp                 ebx, 0x304
            //   730d                 | jae                 0xf

        $sequence_9 = { ff15???????? e8???????? 7368 656c 6c }
            // n = 5, score = 100
            //   ff15????????         |                     
            //   e8????????           |                     
            //   7368                 | jae                 0x6a
            //   656c                 | insb                byte ptr es:[edi], dx
            //   6c                   | insb                byte ptr es:[edi], dx

        $sequence_10 = { 15???????? c705????????00010000 68???????? 68???????? ff15???????? }
            // n = 5, score = 100
            //   15????????           |                     
            //   c705????????00010000     |     
            //   68????????           |                     
            //   68????????           |                     
            //   ff15????????         |                     

        $sequence_11 = { 6832a00000 ff15???????? 8b9da8050000 66894302 }
            // n = 4, score = 100
            //   6832a00000           | push                0xa032
            //   ff15????????         |                     
            //   8b9da8050000         | mov                 ebx, dword ptr [ebp + 0x5a8]
            //   66894302             | mov                 word ptr [ebx + 2], ax

        $sequence_12 = { 8b5d00 894304 8b5d00 81c300040000 }
            // n = 4, score = 100
            //   8b5d00               | mov                 ebx, dword ptr [ebp]
            //   894304               | mov                 dword ptr [ebx + 4], eax
            //   8b5d00               | mov                 ebx, dword ptr [ebp]
            //   81c300040000         | add                 ebx, 0x400

        $sequence_13 = { 90 895830 90 8b1d???????? 90 }
            // n = 5, score = 100
            //   90                   | nop                 
            //   895830               | mov                 dword ptr [eax + 0x30], ebx
            //   90                   | nop                 
            //   8b1d????????         |                     
            //   90                   | nop                 

        $sequence_14 = { 90 895838 90 89c6 90 }
            // n = 5, score = 100
            //   90                   | nop                 
            //   895838               | mov                 dword ptr [eax + 0x38], ebx
            //   90                   | nop                 
            //   89c6                 | mov                 esi, eax
            //   90                   | nop                 

        $sequence_15 = { 31db 90 90 8bbb97114000 90 8938 }
            // n = 6, score = 100
            //   31db                 | xor                 ebx, ebx
            //   90                   | nop                 
            //   90                   | nop                 
            //   8bbb97114000         | mov                 edi, dword ptr [ebx + 0x401197]
            //   90                   | nop                 
            //   8938                 | mov                 dword ptr [eax], edi

    condition:
        7 of them and filesize < 40960
}