rule win_orcarat_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.orcarat."
        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.orcarat"
        malpedia_rule_date = "20260916"
        malpedia_hash = "53a643781c18e08f4a50949af60172d837a0b6f6"
        malpedia_version = "20260917"
        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 = { 57 8bf9 833f00 0f84c1000000 }
            // n = 4, score = 200
            //   57                   | push                edi
            //   8bf9                 | mov                 edi, ecx
            //   833f00               | cmp                 dword ptr [edi], 0
            //   0f84c1000000         | je                  0xc7

        $sequence_1 = { 8b8c2434080000 50 51 55 55 56 }
            // n = 6, score = 200
            //   8b8c2434080000       | mov                 ecx, dword ptr [esp + 0x834]
            //   50                   | push                eax
            //   51                   | push                ecx
            //   55                   | push                ebp
            //   55                   | push                ebp
            //   56                   | push                esi

        $sequence_2 = { c68404380a000000 e8???????? 8dbc24300a0000 83c9ff }
            // n = 4, score = 200
            //   c68404380a000000     | mov                 byte ptr [esp + eax + 0xa38], 0
            //   e8????????           |                     
            //   8dbc24300a0000       | lea                 edi, [esp + 0xa30]
            //   83c9ff               | or                  ecx, 0xffffffff

        $sequence_3 = { 8b8348030000 3bc7 7409 50 ffd6 89bb48030000 bf???????? }
            // n = 7, score = 200
            //   8b8348030000         | mov                 eax, dword ptr [ebx + 0x348]
            //   3bc7                 | cmp                 eax, edi
            //   7409                 | je                  0xb
            //   50                   | push                eax
            //   ffd6                 | call                esi
            //   89bb48030000         | mov                 dword ptr [ebx + 0x348], edi
            //   bf????????           |                     

        $sequence_4 = { 52 e8???????? 8b542410 8d44240c 8d8c2418010000 50 51 }
            // n = 7, score = 200
            //   52                   | push                edx
            //   e8????????           |                     
            //   8b542410             | mov                 edx, dword ptr [esp + 0x10]
            //   8d44240c             | lea                 eax, [esp + 0xc]
            //   8d8c2418010000       | lea                 ecx, [esp + 0x118]
            //   50                   | push                eax
            //   51                   | push                ecx

        $sequence_5 = { c3 53 6880020000 33f6 c744241080020000 e8???????? }
            // n = 6, score = 200
            //   c3                   | ret                 
            //   53                   | push                ebx
            //   6880020000           | push                0x280
            //   33f6                 | xor                 esi, esi
            //   c744241080020000     | mov                 dword ptr [esp + 0x10], 0x280
            //   e8????????           |                     

        $sequence_6 = { c6043000 8b4324 85c0 7451 }
            // n = 4, score = 200
            //   c6043000             | mov                 byte ptr [eax + esi], 0
            //   8b4324               | mov                 eax, dword ptr [ebx + 0x24]
            //   85c0                 | test                eax, eax
            //   7451                 | je                  0x53

        $sequence_7 = { 6a0a f3a4 bf???????? 83c9ff }
            // n = 4, score = 200
            //   6a0a                 | push                0xa
            //   f3a4                 | rep movsb           byte ptr es:[edi], byte ptr [esi]
            //   bf????????           |                     
            //   83c9ff               | or                  ecx, 0xffffffff

        $sequence_8 = { 8b442410 85c0 7661 c68404240c000000 8d8424240c0000 6a00 50 }
            // n = 7, score = 200
            //   8b442410             | mov                 eax, dword ptr [esp + 0x10]
            //   85c0                 | test                eax, eax
            //   7661                 | jbe                 0x63
            //   c68404240c000000     | mov                 byte ptr [esp + eax + 0xc24], 0
            //   8d8424240c0000       | lea                 eax, [esp + 0xc24]
            //   6a00                 | push                0
            //   50                   | push                eax

        $sequence_9 = { 52 e8???????? 8bf0 6a5c 8d7e01 }
            // n = 5, score = 200
            //   52                   | push                edx
            //   e8????????           |                     
            //   8bf0                 | mov                 esi, eax
            //   6a5c                 | push                0x5c
            //   8d7e01               | lea                 edi, [esi + 1]

    condition:
        7 of them and filesize < 114688
}

rule win_orcarat_w0 {
    meta:  
        author = "PwC Cyber Threat Operations :: @tlansec"
        info = "removed MZ@0 and filesize to aid memory scanning"
        sha1 = "253a704acd7952677c70e0c2d787791b8359efe2c92a5e77acea028393a85613"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.orcarat"
        malpedia_version = "20180930"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
    strings:
        $apptype1="application/x-ms-application"
        $apptype2="application/x-ms-xbap"
        $apptype3="application/vnd.ms-xpsdocument"
        $apptype4="application/xaml+xml"
        $apptype5="application/x-shockwave-flash"
        $apptype6="image/pjpeg"
        $err1="Set return time error =   %d!"
        $err2="Set return time   success!"
        $err3="Quit success!"

    condition:
        all of ($apptype*) and 1 of ($err*)
}