rule win_orpcbackdoor_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.orpcbackdoor."
        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.orpcbackdoor"
        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 = { e8???????? 8bc6 c1e002 50 8b85acf8ffff 0fb70485ac820310 }
            // n = 6, score = 100
            //   e8????????           |                     
            //   8bc6                 | mov                 eax, esi
            //   c1e002               | shl                 eax, 2
            //   50                   | push                eax
            //   8b85acf8ffff         | mov                 eax, dword ptr [ebp - 0x754]
            //   0fb70485ac820310     | movzx               eax, word ptr [eax*4 + 0x100382ac]

        $sequence_1 = { 6a00 8b4dfc e8???????? 8b45fc c9 }
            // n = 5, score = 100
            //   6a00                 | push                0
            //   8b4dfc               | mov                 ecx, dword ptr [ebp - 4]
            //   e8????????           |                     
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   c9                   | leave               

        $sequence_2 = { 0f94c0 c3 c705????????80700000 33c0 c705????????01000000 c705????????f0f1ffff c705????????a0450410 }
            // n = 7, score = 100
            //   0f94c0               | sete                al
            //   c3                   | ret                 
            //   c705????????80700000     |     
            //   33c0                 | xor                 eax, eax
            //   c705????????01000000     |     
            //   c705????????f0f1ffff     |     
            //   c705????????a0450410     |     

        $sequence_3 = { e9???????? 8b45e4 2b450c 8b55e8 1b5510 c9 c20c00 }
            // n = 7, score = 100
            //   e9????????           |                     
            //   8b45e4               | mov                 eax, dword ptr [ebp - 0x1c]
            //   2b450c               | sub                 eax, dword ptr [ebp + 0xc]
            //   8b55e8               | mov                 edx, dword ptr [ebp - 0x18]
            //   1b5510               | sbb                 edx, dword ptr [ebp + 0x10]
            //   c9                   | leave               
            //   c20c00               | ret                 0xc

        $sequence_4 = { 59 8945d4 8b45d4 8945e0 8b450c 8945d8 837d0c00 }
            // n = 7, score = 100
            //   59                   | pop                 ecx
            //   8945d4               | mov                 dword ptr [ebp - 0x2c], eax
            //   8b45d4               | mov                 eax, dword ptr [ebp - 0x2c]
            //   8945e0               | mov                 dword ptr [ebp - 0x20], eax
            //   8b450c               | mov                 eax, dword ptr [ebp + 0xc]
            //   8945d8               | mov                 dword ptr [ebp - 0x28], eax
            //   837d0c00             | cmp                 dword ptr [ebp + 0xc], 0

        $sequence_5 = { 32c0 ebf7 8bff 55 8bec 0fb7450e 2500800000 }
            // n = 7, score = 100
            //   32c0                 | xor                 al, al
            //   ebf7                 | jmp                 0xfffffff9
            //   8bff                 | mov                 edi, edi
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   0fb7450e             | movzx               eax, word ptr [ebp + 0xe]
            //   2500800000           | and                 eax, 0x8000

        $sequence_6 = { ff75f4 ff75d4 8d4d0c e8???????? 8d45f8 50 ff75f4 }
            // n = 7, score = 100
            //   ff75f4               | push                dword ptr [ebp - 0xc]
            //   ff75d4               | push                dword ptr [ebp - 0x2c]
            //   8d4d0c               | lea                 ecx, [ebp + 0xc]
            //   e8????????           |                     
            //   8d45f8               | lea                 eax, [ebp - 8]
            //   50                   | push                eax
            //   ff75f4               | push                dword ptr [ebp - 0xc]

        $sequence_7 = { ff7518 ff7510 ff750c ff7508 ff75e0 e8???????? 83c418 }
            // n = 7, score = 100
            //   ff7518               | push                dword ptr [ebp + 0x18]
            //   ff7510               | push                dword ptr [ebp + 0x10]
            //   ff750c               | push                dword ptr [ebp + 0xc]
            //   ff7508               | push                dword ptr [ebp + 8]
            //   ff75e0               | push                dword ptr [ebp - 0x20]
            //   e8????????           |                     
            //   83c418               | add                 esp, 0x18

        $sequence_8 = { 894244 8b4df0 e8???????? ff75f8 ff75f4 8b45f0 ff7044 }
            // n = 7, score = 100
            //   894244               | mov                 dword ptr [edx + 0x44], eax
            //   8b4df0               | mov                 ecx, dword ptr [ebp - 0x10]
            //   e8????????           |                     
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   ff75f4               | push                dword ptr [ebp - 0xc]
            //   8b45f0               | mov                 eax, dword ptr [ebp - 0x10]
            //   ff7044               | push                dword ptr [eax + 0x44]

        $sequence_9 = { cc e9???????? 55 8bec 8b4d08 b8???????? 3908 }
            // n = 7, score = 100
            //   cc                   | int3                
            //   e9????????           |                     
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   8b4d08               | mov                 ecx, dword ptr [ebp + 8]
            //   b8????????           |                     
            //   3908                 | cmp                 dword ptr [eax], ecx

    condition:
        7 of them and filesize < 918528
}