rule win_darkrat_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.darkrat."
        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.darkrat"
        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 = { be???????? 6a01 6a05 894710 e8???????? }
            // n = 5, score = 200
            //   be????????           |                     
            //   6a01                 | push                1
            //   6a05                 | push                5
            //   894710               | mov                 dword ptr [edi + 0x10], eax
            //   e8????????           |                     

        $sequence_1 = { 50 8d45f4 64a300000000 8b4508 8b750c 8945e8 }
            // n = 6, score = 200
            //   50                   | push                eax
            //   8d45f4               | lea                 eax, [ebp - 0xc]
            //   64a300000000         | mov                 dword ptr fs:[0], eax
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   8b750c               | mov                 esi, dword ptr [ebp + 0xc]
            //   8945e8               | mov                 dword ptr [ebp - 0x18], eax

        $sequence_2 = { 884c32ff 83e801 75f2 8b45f0 be???????? 6a01 6a05 }
            // n = 7, score = 200
            //   884c32ff             | mov                 byte ptr [edx + esi - 1], cl
            //   83e801               | sub                 eax, 1
            //   75f2                 | jne                 0xfffffff4
            //   8b45f0               | mov                 eax, dword ptr [ebp - 0x10]
            //   be????????           |                     
            //   6a01                 | push                1
            //   6a05                 | push                5

        $sequence_3 = { 6880000000 8d8570ffffff c745fc01000000 6a00 }
            // n = 4, score = 200
            //   6880000000           | push                0x80
            //   8d8570ffffff         | lea                 eax, [ebp - 0x90]
            //   c745fc01000000       | mov                 dword ptr [ebp - 4], 1
            //   6a00                 | push                0

        $sequence_4 = { 8d8570ffffff 6880000000 50 e8???????? 8dbd70ffffff 83c410 }
            // n = 6, score = 200
            //   8d8570ffffff         | lea                 eax, [ebp - 0x90]
            //   6880000000           | push                0x80
            //   50                   | push                eax
            //   e8????????           |                     
            //   8dbd70ffffff         | lea                 edi, [ebp - 0x90]
            //   83c410               | add                 esp, 0x10

        $sequence_5 = { c745c800000000 c745cc0f000000 c645b800 8d4eff f7f1 3bf2 0f8211010000 }
            // n = 7, score = 200
            //   c745c800000000       | mov                 dword ptr [ebp - 0x38], 0
            //   c745cc0f000000       | mov                 dword ptr [ebp - 0x34], 0xf
            //   c645b800             | mov                 byte ptr [ebp - 0x48], 0
            //   8d4eff               | lea                 ecx, [esi - 1]
            //   f7f1                 | div                 ecx
            //   3bf2                 | cmp                 esi, edx
            //   0f8211010000         | jb                  0x117

        $sequence_6 = { e8???????? 83c408 8945f0 85c0 7446 }
            // n = 5, score = 200
            //   e8????????           |                     
            //   83c408               | add                 esp, 8
            //   8945f0               | mov                 dword ptr [ebp - 0x10], eax
            //   85c0                 | test                eax, eax
            //   7446                 | je                  0x48

        $sequence_7 = { 8bbd68ffffff 3bf8 7723 8d043a 894310 8bc3 }
            // n = 6, score = 200
            //   8bbd68ffffff         | mov                 edi, dword ptr [ebp - 0x98]
            //   3bf8                 | cmp                 edi, eax
            //   7723                 | ja                  0x25
            //   8d043a               | lea                 eax, [edx + edi]
            //   894310               | mov                 dword ptr [ebx + 0x10], eax
            //   8bc3                 | mov                 eax, ebx

        $sequence_8 = { 8975ec 8d4dec c745fc00000000 837d1c10 8d4508 51 }
            // n = 6, score = 200
            //   8975ec               | mov                 dword ptr [ebp - 0x14], esi
            //   8d4dec               | lea                 ecx, [ebp - 0x14]
            //   c745fc00000000       | mov                 dword ptr [ebp - 4], 0
            //   837d1c10             | cmp                 dword ptr [ebp + 0x1c], 0x10
            //   8d4508               | lea                 eax, [ebp + 8]
            //   51                   | push                ecx

        $sequence_9 = { c645b800 8d4eff f7f1 3bf2 0f8211010000 }
            // n = 5, score = 200
            //   c645b800             | mov                 byte ptr [ebp - 0x48], 0
            //   8d4eff               | lea                 ecx, [esi - 1]
            //   f7f1                 | div                 ecx
            //   3bf2                 | cmp                 esi, edx
            //   0f8211010000         | jb                  0x117

    condition:
        7 of them and filesize < 884736
}

rule win_darkrat_w0 {
    meta:
        author = "Albert Zsigovits"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.darkrat"
        malpedia_version = "20191012"
        malpedia_license = "CC BY-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
            
    strings:
	    $pdb = "C:\\Users\\darkspider" ascii wide
	    $cmd = "cmd.exe /C ping 127.0.0.1 -n 1 -w 3000 > Nul & Del /f /q \"%s\"" ascii wide

	    $guid1 = "SOFTWARE\\Microsoft\\Cryptography" ascii wide
	    $guid2 = "MachineGuid" ascii wide

	    $persi1 = "Software\\Microsoft\\Windows\\CurrentVersion\\Run" ascii wide
	    $persi2 = "WinSystem32" ascii wide

	    $bin = "pastebin.com/raw/" ascii wide
	    $import0 = "NtUnmapViewOfSection" ascii wide
	    $import1 = "WriteProcessMemory" ascii wide
	    $import2 = "ResumeThread" ascii wide
	    $import3 = "GetNativeSystemInfo" ascii wide
	    $import4 = "URLOpenBlockingStream" ascii wide
	    $import5 = "VirtualFree" ascii wide
	    $import6 = "VirtualAlloc" ascii wide
	    $import7 = "GetModuleHandle" ascii wide
	    $import8 = "LoadLibrary" ascii wide
	    $import9 = "CreateMutex" ascii wide

	    $vbs0 = "Set objShell = WScript.CreateObject(\"WScript.Shell\")" ascii wide
	    $vbs1 = "Set objWMIService = GetObject(\"winmgmts:\\\\\" & sComputerName & \"\\root\\cimv2\")" ascii wide
	    $vbs2 = "Set objItems = objWMIService.ExecQuery(sQuery)" ascii wide
	    $vbs3 = "sQuery = \"SELECT * FROM Win32_Process\"" ascii wide
	    $vbs4 = "wscript.exe" ascii wide

	    $net0 = "POST" ascii wide
	    $net1 = "&taskid=" ascii wide
	    $net2 = "&taskstatus=" ascii wide
	    $net3 = "&spreadtag=" ascii wide
	    $net4 = "&operingsystem=" ascii wide
	    $net5 = "&arch=" ascii wide
	    $net6 = "&cpuName=" ascii wide
	    $net7 = "&gpuName=" ascii wide
	    $net8 = "&botversion=" ascii wide
	    $net9 = "&antivirus=" ascii wide
	    $net10 = "&netFramework4=" ascii wide
	    $net11 = "&netFramework35=" ascii wide
	    $net12 = "&netFramework3=" ascii wide
	    $net13 = "&netFramework2=" ascii wide
	    $net14 = "&installedRam=" ascii wide
	    $net15 = "&aornot=" ascii wide
	    $net16 = "&computername=" ascii wide
	    $net17 = "hwid=" ascii wide
	    $net18 = "request=" ascii wide

    condition:
	    $pdb or $cmd or ( all of ($guid*) and all of ($persi*) ) or ( 3 of ($vbs*) ) or ( all of ($import*) and $bin ) or ( all of ($net*) )
}

rule win_darkrat_w1 {
    meta:
        description = "Darkrat"
        author = "James_inthe_box"
        reference = "https://github.com/albertzsigovits/malware-writeups/tree/master/DarkRATv2"
        date = "2019/08"
        maltype = "RAT"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.darkrat"
        malpedia_version = "20191012"
        malpedia_license = "CC BY-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
 
    strings:
        $string1 = "Set objShell = WScript.CreateObject(\"WScript.Shell\")"
        $string2 = "&taskstatus="
        $string3 = "network reset"
        $string4 = "text/plain"
        $string5 = "&antivirus="
        $string6 = "request="
        $string7 = "&arch="
 
    condition:
        all of ($string*)
}