rule win_orcarat_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        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 = "20260422"
        malpedia_hash = "a182e35da64e6d71cb55f125c4d4225196523f14"
        malpedia_version = "20260504"
        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 = { 8d442420 52 50 6a01 8bcf e8???????? 85c0 }
            // n = 7, score = 200
            //   8d442420             | lea                 eax, [esp + 0x20]
            //   52                   | push                edx
            //   50                   | push                eax
            //   6a01                 | push                1
            //   8bcf                 | mov                 ecx, edi
            //   e8????????           |                     
            //   85c0                 | test                eax, eax

        $sequence_1 = { 8d8424405a0000 52 50 a1???????? 8d8c2438020000 }
            // n = 5, score = 200
            //   8d8424405a0000       | lea                 eax, [esp + 0x5a40]
            //   52                   | push                edx
            //   50                   | push                eax
            //   a1????????           |                     
            //   8d8c2438020000       | lea                 ecx, [esp + 0x238]

        $sequence_2 = { 52 f3a4 8d7c2424 83c9ff f2ae f7d1 8d842428050000 }
            // n = 7, score = 200
            //   52                   | push                edx
            //   f3a4                 | rep movsb           byte ptr es:[edi], byte ptr [esi]
            //   8d7c2424             | lea                 edi, [esp + 0x24]
            //   83c9ff               | or                  ecx, 0xffffffff
            //   f2ae                 | repne scasb         al, byte ptr es:[edi]
            //   f7d1                 | not                 ecx
            //   8d842428050000       | lea                 eax, [esp + 0x528]

        $sequence_3 = { f7d1 2bf9 8d54241c 8bc1 8bf7 8bfa c1e902 }
            // n = 7, score = 200
            //   f7d1                 | not                 ecx
            //   2bf9                 | sub                 edi, ecx
            //   8d54241c             | lea                 edx, [esp + 0x1c]
            //   8bc1                 | mov                 eax, ecx
            //   8bf7                 | mov                 esi, edi
            //   8bfa                 | mov                 edi, edx
            //   c1e902               | shr                 ecx, 2

        $sequence_4 = { 2bf1 56 52 50 e8???????? 8b84242c500000 }
            // n = 6, score = 200
            //   2bf1                 | sub                 esi, ecx
            //   56                   | push                esi
            //   52                   | push                edx
            //   50                   | push                eax
            //   e8????????           |                     
            //   8b84242c500000       | mov                 eax, dword ptr [esp + 0x502c]

        $sequence_5 = { c3 ff25???????? 55 8bec 837d100a }
            // n = 5, score = 200
            //   c3                   | ret                 
            //   ff25????????         |                     
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   837d100a             | cmp                 dword ptr [ebp + 0x10], 0xa

        $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 = { 51 52 6813000020 56 c744242801000000 c744243404000000 }
            // n = 6, score = 200
            //   51                   | push                ecx
            //   52                   | push                edx
            //   6813000020           | push                0x20000013
            //   56                   | push                esi
            //   c744242801000000     | mov                 dword ptr [esp + 0x28], 1
            //   c744243404000000     | mov                 dword ptr [esp + 0x34], 4

        $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 = { 89bbfc020000 8b834c030000 3bc7 7409 50 }
            // n = 5, score = 200
            //   89bbfc020000         | mov                 dword ptr [ebx + 0x2fc], edi
            //   8b834c030000         | mov                 eax, dword ptr [ebx + 0x34c]
            //   3bc7                 | cmp                 eax, edi
            //   7409                 | je                  0xb
            //   50                   | push                eax

    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*)
}