rule win_tinyloader_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.tinyloader."
        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.tinyloader"
        malpedia_rule_date = "20230124"
        malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686"
        malpedia_version = "20230125"
        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 = { 29d8 90 31db 90 31c9 }
            // n = 5, score = 100
            //   29d8                 | sub                 eax, ebx
            //   90                   | nop                 
            //   31db                 | xor                 ebx, ebx
            //   90                   | nop                 
            //   31c9                 | xor                 ecx, ecx

        $sequence_1 = { 8985a8050000 0500080000 894508 0500200000 894518 0500200000 894510 }
            // n = 7, score = 100
            //   8985a8050000         | mov                 dword ptr [ebp + 0x5a8], eax
            //   0500080000           | add                 eax, 0x800
            //   894508               | mov                 dword ptr [ebp + 8], eax
            //   0500200000           | add                 eax, 0x2000
            //   894518               | mov                 dword ptr [ebp + 0x18], eax
            //   0500200000           | add                 eax, 0x2000
            //   894510               | mov                 dword ptr [ebp + 0x10], eax

        $sequence_2 = { 81fb04030000 730d 90 83c004 }
            // n = 4, score = 100
            //   81fb04030000         | cmp                 ebx, 0x304
            //   730d                 | jae                 0xf
            //   90                   | nop                 
            //   83c004               | add                 eax, 4

        $sequence_3 = { 637574 6541 0050ff 15???????? c705????????00010000 68???????? 68???????? }
            // n = 7, score = 100
            //   637574               | arpl                word ptr [ebp + 0x74], si
            //   6541                 | inc                 ecx
            //   0050ff               | add                 byte ptr [eax - 1], dl
            //   15????????           |                     
            //   c705????????00010000     |     
            //   68????????           |                     
            //   68????????           |                     

        $sequence_4 = { 0500080000 894520 ffb5a0050000 6802020000 }
            // n = 4, score = 100
            //   0500080000           | add                 eax, 0x800
            //   894520               | mov                 dword ptr [ebp + 0x20], eax
            //   ffb5a0050000         | push                dword ptr [ebp + 0x5a0]
            //   6802020000           | push                0x202

        $sequence_5 = { 90 895830 90 8b1d???????? 90 895838 }
            // n = 6, score = 100
            //   90                   | nop                 
            //   895830               | mov                 dword ptr [eax + 0x30], ebx
            //   90                   | nop                 
            //   8b1d????????         |                     
            //   90                   | nop                 
            //   895838               | mov                 dword ptr [eax + 0x38], ebx

        $sequence_6 = { 7302 ebc3 8b5d00 8b4308 3b8558080000 7402 }
            // n = 6, score = 100
            //   7302                 | jae                 4
            //   ebc3                 | jmp                 0xffffffc5
            //   8b5d00               | mov                 ebx, dword ptr [ebp]
            //   8b4308               | mov                 eax, dword ptr [ebx + 8]
            //   3b8558080000         | cmp                 eax, dword ptr [ebp + 0x858]
            //   7402                 | je                  4

        $sequence_7 = { 895838 90 89c6 90 0500400100 }
            // n = 5, score = 100
            //   895838               | mov                 dword ptr [eax + 0x38], ebx
            //   90                   | nop                 
            //   89c6                 | mov                 esi, eax
            //   90                   | nop                 
            //   0500400100           | add                 eax, 0x14000

        $sequence_8 = { 8b5510 01da 8b12 8b4500 83c00c }
            // n = 5, score = 100
            //   8b5510               | mov                 edx, dword ptr [ebp + 0x10]
            //   01da                 | add                 edx, ebx
            //   8b12                 | mov                 edx, dword ptr [edx]
            //   8b4500               | mov                 eax, dword ptr [ebp]
            //   83c00c               | add                 eax, 0xc

        $sequence_9 = { ffb5a8050000 ffb5b8050000 ff15???????? 83f8ff 7505 }
            // n = 5, score = 100
            //   ffb5a8050000         | push                dword ptr [ebp + 0x5a8]
            //   ffb5b8050000         | push                dword ptr [ebp + 0x5b8]
            //   ff15????????         |                     
            //   83f8ff               | cmp                 eax, -1
            //   7505                 | jne                 7

        $sequence_10 = { c131da 4f 75d5 f7d2 f7d1 5b 89d0 }
            // n = 7, score = 100
            //   c131da               | sal                 dword ptr [ecx], 0xda
            //   4f                   | dec                 edi
            //   75d5                 | jne                 0xffffffd7
            //   f7d2                 | not                 edx
            //   f7d1                 | not                 ecx
            //   5b                   | pop                 ebx
            //   89d0                 | mov                 eax, edx

        $sequence_11 = { 6a00 ff33 ff7500 ffb5b8050000 }
            // n = 4, score = 100
            //   6a00                 | push                0
            //   ff33                 | push                dword ptr [ebx]
            //   ff7500               | push                dword ptr [ebp]
            //   ffb5b8050000         | push                dword ptr [ebp + 0x5b8]

        $sequence_12 = { 90 8998f8070000 90 8b1d???????? 90 895830 }
            // n = 6, score = 100
            //   90                   | nop                 
            //   8998f8070000         | mov                 dword ptr [eax + 0x7f8], ebx
            //   90                   | nop                 
            //   8b1d????????         |                     
            //   90                   | nop                 
            //   895830               | mov                 dword ptr [eax + 0x30], ebx

        $sequence_13 = { 83e80c 39c3 7321 3d80020000 731a 83f800 7615 }
            // n = 7, score = 100
            //   83e80c               | sub                 eax, 0xc
            //   39c3                 | cmp                 ebx, eax
            //   7321                 | jae                 0x23
            //   3d80020000           | cmp                 eax, 0x280
            //   731a                 | jae                 0x1c
            //   83f800               | cmp                 eax, 0
            //   7615                 | jbe                 0x17

        $sequence_14 = { c78540050000000000ba 6a40 6800300000 6800400100 6a00 ff15???????? }
            // n = 6, score = 100
            //   c78540050000000000ba     | mov    dword ptr [ebp + 0x540], 0xba000000
            //   6a40                 | push                0x40
            //   6800300000           | push                0x3000
            //   6800400100           | push                0x14000
            //   6a00                 | push                0
            //   ff15????????         |                     

        $sequence_15 = { 90 8938 90 81fb04030000 }
            // n = 4, score = 100
            //   90                   | nop                 
            //   8938                 | mov                 dword ptr [eax], edi
            //   90                   | nop                 
            //   81fb04030000         | cmp                 ebx, 0x304

    condition:
        7 of them and filesize < 40960
}