rule win_webmonitor_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        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 = "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 = { 000d???????? 04e4 fd 0468 ff05???????? 000d???????? 04b8 }
            // n = 7, score = 200
            //   000d????????         |                     
            //   04e4                 | add                 al, 0xe4
            //   fd                   | std                 
            //   0468                 | add                 al, 0x68
            //   ff05????????         |                     
            //   000d????????         |                     
            //   04b8                 | add                 al, 0xb8

        $sequence_1 = { 03c1 99 f7fb 47 }
            // n = 4, score = 200
            //   03c1                 | add                 eax, ecx
            //   99                   | cdq                 
            //   f7fb                 | idiv                ebx
            //   47                   | inc                 edi

        $sequence_2 = { ffe1 ba???????? b9???????? ffe1 ba???????? }
            // n = 5, score = 200
            //   ffe1                 | jmp                 ecx
            //   ba????????           |                     
            //   b9????????           |                     
            //   ffe1                 | jmp                 ecx
            //   ba????????           |                     

        $sequence_3 = { fe04e4 fd 04e0 fd ff01 04e0 fd }
            // n = 7, score = 200
            //   fe04e4               | inc                 byte ptr [esp]
            //   fd                   | std                 
            //   04e0                 | add                 al, 0xe0
            //   fd                   | std                 
            //   ff01                 | inc                 dword ptr [ecx]
            //   04e0                 | add                 al, 0xe0
            //   fd                   | std                 

        $sequence_4 = { 04c8 fe04ec fd 04e8 fd ff01 }
            // n = 6, score = 200
            //   04c8                 | add                 al, 0xc8
            //   fe04ec               | inc                 byte ptr [esp + ebp*8]
            //   fd                   | std                 
            //   04e8                 | add                 al, 0xe8
            //   fd                   | std                 
            //   ff01                 | inc                 dword ptr [ecx]

        $sequence_5 = { 0f5ac0 50 51 51 f20f110424 e8???????? d91b }
            // n = 7, score = 200
            //   0f5ac0               | cvtps2pd            xmm0, xmm0
            //   50                   | push                eax
            //   51                   | push                ecx
            //   51                   | push                ecx
            //   f20f110424           | movsd               qword ptr [esp], xmm0
            //   e8????????           |                     
            //   d91b                 | fstp                dword ptr [ebx]

        $sequence_6 = { 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_7 = { 0f437520 ff15???????? 8d044501000000 50 }
            // n = 4, score = 200
            //   0f437520             | cmovae              esi, dword ptr [ebp + 0x20]
            //   ff15????????         |                     
            //   8d044501000000       | lea                 eax, [eax*2 + 1]
            //   50                   | push                eax

        $sequence_8 = { 0fb6c0 d3e0 8b4de0 03c8 }
            // n = 4, score = 200
            //   0fb6c0               | movzx               eax, al
            //   d3e0                 | shl                 eax, cl
            //   8b4de0               | mov                 ecx, dword ptr [ebp - 0x20]
            //   03c8                 | add                 ecx, eax

        $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 = { 3001 a3???????? 30ff 9e 6c 68ff080800 }
            // n = 6, score = 200
            //   3001                 | xor                 byte ptr [ecx], al
            //   a3????????           |                     
            //   30ff                 | xor                 bh, bh
            //   9e                   | sahf                
            //   6c                   | insb                byte ptr es:[edi], dx
            //   68ff080800           | push                0x808ff

        $sequence_11 = { 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_12 = { 38644400 44 8a4100 047e }
            // n = 4, score = 200
            //   38644400             | cmp                 byte ptr [esp + eax*2], ah
            //   44                   | inc                 esp
            //   8a4100               | mov                 al, byte ptr [ecx]
            //   047e                 | add                 al, 0x7e

        $sequence_13 = { 00e8 17 42 0048a5 }
            // n = 4, score = 200
            //   00e8                 | add                 al, ch
            //   17                   | pop                 ss
            //   42                   | inc                 edx
            //   0048a5               | add                 byte ptr [eax - 0x5b], cl

        $sequence_14 = { 49 81c900ffffff 41 898f04040000 }
            // n = 4, score = 200
            //   49                   | dec                 ecx
            //   81c900ffffff         | or                  ecx, 0xffffff00
            //   41                   | inc                 ecx
            //   898f04040000         | mov                 dword ptr [edi + 0x404], ecx

        $sequence_15 = { 0f4305???????? 33c9 6800900100 668908 }
            // n = 4, score = 200
            //   0f4305????????       |                     
            //   33c9                 | xor                 ecx, ecx
            //   6800900100           | push                0x19000
            //   668908               | mov                 word ptr [eax], cx

    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*)
}