rule win_webmonitor_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.webmonitor."
        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.webmonitor"
        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 = { 0fb6c0 6a0e 33f0 e8???????? ff75dc 0fb6c0 }
            // n = 6, score = 200
            //   0fb6c0               | movzx               eax, al
            //   6a0e                 | push                0xe
            //   33f0                 | xor                 esi, eax
            //   e8????????           |                     
            //   ff75dc               | push                dword ptr [ebp - 0x24]
            //   0fb6c0               | movzx               eax, al

        $sequence_1 = { 9e 6c 68ff080800 8a3401 a3???????? 0800 8a30 }
            // n = 7, score = 200
            //   9e                   | sahf                
            //   6c                   | insb                byte ptr es:[edi], dx
            //   68ff080800           | push                0x808ff
            //   8a3401               | mov                 dh, byte ptr [ecx + eax]
            //   a3????????           |                     
            //   0800                 | or                  byte ptr [eax], al
            //   8a30                 | mov                 dh, byte ptr [eax]

        $sequence_2 = { 33c0 894df0 894f10 c7471407000000 668907 894dfc }
            // n = 6, score = 200
            //   33c0                 | xor                 eax, eax
            //   894df0               | mov                 dword ptr [ebp - 0x10], ecx
            //   894f10               | mov                 dword ptr [edi + 0x10], ecx
            //   c7471407000000       | mov                 dword ptr [edi + 0x14], 7
            //   668907               | mov                 word ptr [edi], ax
            //   894dfc               | mov                 dword ptr [ebp - 4], ecx

        $sequence_3 = { 33c9 83c410 2bc1 7414 }
            // n = 4, score = 200
            //   33c9                 | xor                 ecx, ecx
            //   83c410               | add                 esp, 0x10
            //   2bc1                 | sub                 eax, ecx
            //   7414                 | je                  0x16

        $sequence_4 = { 1b6100 43 ec fe04ec }
            // n = 4, score = 200
            //   1b6100               | sbb                 esp, dword ptr [ecx]
            //   43                   | inc                 ebx
            //   ec                   | in                  al, dx
            //   fe04ec               | inc                 byte ptr [esp + ebp*8]

        $sequence_5 = { d94200 a4 44 43 00dc 7442 000477 }
            // n = 7, score = 200
            //   d94200               | fld                 dword ptr [edx]
            //   a4                   | movsb               byte ptr es:[edi], byte ptr [esi]
            //   44                   | inc                 esp
            //   43                   | inc                 ebx
            //   00dc                 | add                 ah, bl
            //   7442                 | je                  0x44
            //   000477               | add                 byte ptr [edi + esi*2], al

        $sequence_6 = { a1???????? 41 0094be4100d891 41 }
            // n = 4, score = 200
            //   a1????????           |                     
            //   41                   | inc                 ecx
            //   0094be4100d891       | add                 byte ptr [esi + edi*4 - 0x6e27ffbf], dl
            //   41                   | inc                 ecx

        $sequence_7 = { 0338 8bc6 99 83c004 8901 }
            // n = 5, score = 200
            //   0338                 | add                 edi, dword ptr [eax]
            //   8bc6                 | mov                 eax, esi
            //   99                   | cdq                 
            //   83c004               | add                 eax, 4
            //   8901                 | mov                 dword ptr [ecx], eax

        $sequence_8 = { 50 895de8 c745ec0f000000 885dd8 }
            // n = 4, score = 200
            //   50                   | push                eax
            //   895de8               | mov                 dword ptr [ebp - 0x18], ebx
            //   c745ec0f000000       | mov                 dword ptr [ebp - 0x14], 0xf
            //   885dd8               | mov                 byte ptr [ebp - 0x28], bl

        $sequence_9 = { 2bf0 8bc1 99 83e203 03c2 c1f802 2bf8 }
            // n = 7, score = 200
            //   2bf0                 | sub                 esi, eax
            //   8bc1                 | mov                 eax, ecx
            //   99                   | cdq                 
            //   83e203               | and                 edx, 3
            //   03c2                 | add                 eax, edx
            //   c1f802               | sar                 eax, 2
            //   2bf8                 | sub                 edi, eax

        $sequence_10 = { 00e8 894100 dc2442 00e8 17 42 0048a5 }
            // n = 7, score = 200
            //   00e8                 | add                 al, ch
            //   894100               | mov                 dword ptr [ecx], eax
            //   dc2442               | fsub                qword ptr [edx + eax*2]
            //   00e8                 | add                 al, ch
            //   17                   | pop                 ss
            //   42                   | inc                 edx
            //   0048a5               | add                 byte ptr [eax - 0x5b], cl

        $sequence_11 = { 04e4 fd 0468 ff05???????? 000d???????? }
            // n = 5, score = 200
            //   04e4                 | add                 al, 0xe4
            //   fd                   | std                 
            //   0468                 | add                 al, 0x68
            //   ff05????????         |                     
            //   000d????????         |                     

        $sequence_12 = { 0f434520 50 ff75c8 ff15???????? }
            // n = 4, score = 200
            //   0f434520             | cmovae              eax, dword ptr [ebp + 0x20]
            //   50                   | push                eax
            //   ff75c8               | push                dword ptr [ebp - 0x38]
            //   ff15????????         |                     

        $sequence_13 = { ff01 04e8 fd 0512002413 000d???????? 04e4 fd }
            // n = 7, score = 200
            //   ff01                 | inc                 dword ptr [ecx]
            //   04e8                 | add                 al, 0xe8
            //   fd                   | std                 
            //   0512002413           | add                 eax, 0x13240012
            //   000d????????         |                     
            //   04e4                 | add                 al, 0xe4
            //   fd                   | std                 

        $sequence_14 = { 03c6 50 8d0433 50 e8???????? 83c418 ebb0 }
            // n = 7, score = 200
            //   03c6                 | add                 eax, esi
            //   50                   | push                eax
            //   8d0433               | lea                 eax, [ebx + esi]
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c418               | add                 esp, 0x18
            //   ebb0                 | jmp                 0xffffffb2

        $sequence_15 = { 0094be4100d891 41 0084e84100a872 42 00a06a4200f8 }
            // n = 5, score = 200
            //   0094be4100d891       | add                 byte ptr [esi + edi*4 - 0x6e27ffbf], dl
            //   41                   | inc                 ecx
            //   0084e84100a872       | add                 byte ptr [eax + ebp*8 + 0x72a80041], al
            //   42                   | inc                 edx
            //   00a06a4200f8         | add                 byte ptr [eax - 0x7ffbd96], ah

    condition:
        7 of them and filesize < 1984512
}

rule win_webmonitor_w0 {
    meta:
        description = "Revcode RAT"
        author = "James_inthe_box"
        reference = "ee1b9659f2193896ce3469b5f90b82af3caffcba428e8524be5a9fdf391d8dd8"
        date = "2020/02"
        maltype = "RAT"
        source = "https://pastebin.com/M2k5Vg3c"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.webmonitor"
        malpedia_version = "20200304"
        malpedia_sharing = "TLP:WHITE"
        malpedia_license = ""

    strings:
        $string1 = "SCREEN_STREAM_START"
        $string2 = "CLIPBOARD_SET"
        $string3 = "SERVICES_RESUME"
        $string4 = "KEYLOG:"
        $string5 = "WEBCAM_DRIVERS"
        $string6 = "image.bmp" wide
        $string7 = "APPACTIVATE" wide
 
    condition:
        all of ($string*)
}