rule win_tinyloader_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-08-05"
        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 = "20220805"
        malpedia_hash = "6ec06c64bcfdbeda64eff021c766b4ce34542b71"
        malpedia_version = "20220808"
        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 = { 83bb0004000000 750a c783000400000c000000 8b8540050000 8b5d00 894308 8b85f8070000 }
            // n = 7, score = 100
            //   83bb0004000000       | cmp                 dword ptr [ebx + 0x400], 0
            //   750a                 | jne                 0xc
            //   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]

        $sequence_1 = { 53 68656c6c45 7865 637574 6541 0050ff }
            // n = 6, score = 100
            //   53                   | push                ebx
            //   68656c6c45           | push                0x456c6c65
            //   7865                 | js                  0x67
            //   637574               | arpl                word ptr [ebp + 0x74], si
            //   6541                 | inc                 ecx
            //   0050ff               | add                 byte ptr [eax - 1], dl

        $sequence_2 = { eb28 83e80c 39c3 7321 3d80020000 731a }
            // n = 6, score = 100
            //   eb28                 | jmp                 0x2a
            //   83e80c               | sub                 eax, 0xc
            //   39c3                 | cmp                 ebx, eax
            //   7321                 | jae                 0x23
            //   3d80020000           | cmp                 eax, 0x280
            //   731a                 | jae                 0x1c

        $sequence_3 = { 8d9d40050000 53 50 ff95b0020000 83bd4005000001 }
            // n = 5, score = 100
            //   8d9d40050000         | lea                 ebx, [ebp + 0x540]
            //   53                   | push                ebx
            //   50                   | push                eax
            //   ff95b0020000         | call                dword ptr [ebp + 0x2b0]
            //   83bd4005000001       | cmp                 dword ptr [ebp + 0x540], 1

        $sequence_4 = { 83f800 7615 8b5510 01da 8b12 8b4500 }
            // n = 6, score = 100
            //   83f800               | cmp                 eax, 0
            //   7615                 | jbe                 0x17
            //   8b5510               | mov                 edx, dword ptr [ebp + 0x10]
            //   01da                 | add                 edx, ebx
            //   8b12                 | mov                 edx, dword ptr [edx]
            //   8b4500               | mov                 eax, dword ptr [ebp]

        $sequence_5 = { 89c6 90 0500400100 90 31db 90 90 }
            // n = 7, score = 100
            //   89c6                 | mov                 esi, eax
            //   90                   | nop                 
            //   0500400100           | add                 eax, 0x14000
            //   90                   | nop                 
            //   31db                 | xor                 ebx, ebx
            //   90                   | nop                 
            //   90                   | nop                 

        $sequence_6 = { ffd0 31db 8b4500 8b8000040000 }
            // n = 4, score = 100
            //   ffd0                 | call                eax
            //   31db                 | xor                 ebx, ebx
            //   8b4500               | mov                 eax, dword ptr [ebp]
            //   8b8000040000         | mov                 eax, dword ptr [eax + 0x400]

        $sequence_7 = { 8b1d???????? 90 895830 90 8b1d???????? 90 }
            // n = 6, score = 100
            //   8b1d????????         |                     
            //   90                   | nop                 
            //   895830               | mov                 dword ptr [eax + 0x30], ebx
            //   90                   | nop                 
            //   8b1d????????         |                     
            //   90                   | nop                 

        $sequence_8 = { 6800300000 6800800200 6a00 ff15???????? 90 }
            // n = 5, score = 100
            //   6800300000           | push                0x3000
            //   6800800200           | push                0x28000
            //   6a00                 | push                0
            //   ff15????????         |                     
            //   90                   | nop                 

        $sequence_9 = { 31d2 8b4d00 8b4904 8b5500 01da 83c20c 310a }
            // n = 7, score = 100
            //   31d2                 | xor                 edx, edx
            //   8b4d00               | mov                 ecx, dword ptr [ebp]
            //   8b4904               | mov                 ecx, dword ptr [ecx + 4]
            //   8b5500               | mov                 edx, dword ptr [ebp]
            //   01da                 | add                 edx, ebx
            //   83c20c               | add                 edx, 0xc
            //   310a                 | xor                 dword ptr [edx], ecx

        $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 = { c78540050000000000ba 6a40 6800300000 6800400100 6a00 }
            // n = 5, score = 100
            //   c78540050000000000ba     | mov    dword ptr [ebp + 0x540], 0xba000000
            //   6a40                 | push                0x40
            //   6800300000           | push                0x3000
            //   6800400100           | push                0x14000
            //   6a00                 | push                0

        $sequence_12 = { 83f8ff 7505 e9???????? 8b5d00 81c300040000 }
            // n = 5, score = 100
            //   83f8ff               | cmp                 eax, -1
            //   7505                 | jne                 7
            //   e9????????           |                     
            //   8b5d00               | mov                 ebx, dword ptr [ebp]
            //   81c300040000         | add                 ebx, 0x400

        $sequence_13 = { 81fb04030000 730d 90 83c004 90 83c304 90 }
            // n = 7, score = 100
            //   81fb04030000         | cmp                 ebx, 0x304
            //   730d                 | jae                 0xf
            //   90                   | nop                 
            //   83c004               | add                 eax, 4
            //   90                   | nop                 
            //   83c304               | add                 ebx, 4
            //   90                   | nop                 

        $sequence_14 = { 90 90 8bbb97114000 90 8938 90 }
            // n = 6, score = 100
            //   90                   | nop                 
            //   90                   | nop                 
            //   8bbb97114000         | mov                 edi, dword ptr [ebx + 0x401197]
            //   90                   | nop                 
            //   8938                 | mov                 dword ptr [eax], edi
            //   90                   | nop                 

        $sequence_15 = { f7d1 5b 89d0 c1c010 6689c8 90 6a40 }
            // n = 7, score = 100
            //   f7d1                 | not                 ecx
            //   5b                   | pop                 ebx
            //   89d0                 | mov                 eax, edx
            //   c1c010               | rol                 eax, 0x10
            //   6689c8               | mov                 ax, cx
            //   90                   | nop                 
            //   6a40                 | push                0x40

    condition:
        7 of them and filesize < 40960
}