rule win_koadic_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.koadic."
        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.koadic"
        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 = { ff15???????? 57 57 6a31 }
            // n = 4, score = 100
            //   ff15????????         |                     
            //   57                   | push                edi
            //   57                   | push                edi
            //   6a31                 | push                0x31

        $sequence_1 = { 0a02 0a0a 03040a 0506070a0a 0a0a 0a0a 0a02 }
            // n = 7, score = 100
            //   0a02                 | or                  al, byte ptr [edx]
            //   0a0a                 | or                  cl, byte ptr [edx]
            //   03040a               | add                 eax, dword ptr [edx + ecx]
            //   0506070a0a           | add                 eax, 0xa0a0706
            //   0a0a                 | or                  cl, byte ptr [edx]
            //   0a0a                 | or                  cl, byte ptr [edx]
            //   0a02                 | or                  al, byte ptr [edx]

        $sequence_2 = { e8???????? 6801000000 e9???????? 8b1424 ff35???????? e8???????? 58 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   6801000000           | push                1
            //   e9????????           |                     
            //   8b1424               | mov                 edx, dword ptr [esp]
            //   ff35????????         |                     
            //   e8????????           |                     
            //   58                   | pop                 eax

        $sequence_3 = { 0f8ed4000000 8bc7 99 2bc2 55 8b6c2420 8b4d00 }
            // n = 7, score = 100
            //   0f8ed4000000         | jle                 0xda
            //   8bc7                 | mov                 eax, edi
            //   99                   | cdq                 
            //   2bc2                 | sub                 eax, edx
            //   55                   | push                ebp
            //   8b6c2420             | mov                 ebp, dword ptr [esp + 0x20]
            //   8b4d00               | mov                 ecx, dword ptr [ebp]

        $sequence_4 = { 8bf0 eb12 397708 0f84f9000000 8b4710 8b4f04 }
            // n = 6, score = 100
            //   8bf0                 | mov                 esi, eax
            //   eb12                 | jmp                 0x14
            //   397708               | cmp                 dword ptr [edi + 8], esi
            //   0f84f9000000         | je                  0xff
            //   8b4710               | mov                 eax, dword ptr [edi + 0x10]
            //   8b4f04               | mov                 ecx, dword ptr [edi + 4]

        $sequence_5 = { 397e2c 7415 57 ff75fc 897e2c 57 6835330000 }
            // n = 7, score = 100
            //   397e2c               | cmp                 dword ptr [esi + 0x2c], edi
            //   7415                 | je                  0x17
            //   57                   | push                edi
            //   ff75fc               | push                dword ptr [ebp - 4]
            //   897e2c               | mov                 dword ptr [esi + 0x2c], edi
            //   57                   | push                edi
            //   6835330000           | push                0x3335

        $sequence_6 = { 8b7d10 85ff 0f84a4020000 56 8b37 83feff 0f8482020000 }
            // n = 7, score = 100
            //   8b7d10               | mov                 edi, dword ptr [ebp + 0x10]
            //   85ff                 | test                edi, edi
            //   0f84a4020000         | je                  0x2aa
            //   56                   | push                esi
            //   8b37                 | mov                 esi, dword ptr [edi]
            //   83feff               | cmp                 esi, -1
            //   0f8482020000         | je                  0x288

        $sequence_7 = { 011424 ff35???????? e8???????? 89c5 c7450001000000 ff35???????? e8???????? }
            // n = 7, score = 100
            //   011424               | add                 dword ptr [esp], edx
            //   ff35????????         |                     
            //   e8????????           |                     
            //   89c5                 | mov                 ebp, eax
            //   c7450001000000       | mov                 dword ptr [ebp], 1
            //   ff35????????         |                     
            //   e8????????           |                     

        $sequence_8 = { 85ff 743a 8a0f 33d2 8bf7 8bc7 }
            // n = 6, score = 100
            //   85ff                 | test                edi, edi
            //   743a                 | je                  0x3c
            //   8a0f                 | mov                 cl, byte ptr [edi]
            //   33d2                 | xor                 edx, edx
            //   8bf7                 | mov                 esi, edi
            //   8bc7                 | mov                 eax, edi

        $sequence_9 = { 894508 8b460c 893c81 ff460c 53 ff75ec ff36 }
            // n = 7, score = 100
            //   894508               | mov                 dword ptr [ebp + 8], eax
            //   8b460c               | mov                 eax, dword ptr [esi + 0xc]
            //   893c81               | mov                 dword ptr [ecx + eax*4], edi
            //   ff460c               | inc                 dword ptr [esi + 0xc]
            //   53                   | push                ebx
            //   ff75ec               | push                dword ptr [ebp - 0x14]
            //   ff36                 | push                dword ptr [esi]

    condition:
        7 of them and filesize < 180224
}