rule win_webmonitor_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        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 = "20230124"
        malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686"
        malpedia_version = "20230125"
        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 = { 1c8a ffcd 0c28 f3a3???????? b02a }
            // n = 5, score = 200
            //   1c8a                 | sbb                 al, 0x8a
            //   ffcd                 | dec                 ebp
            //   0c28                 | or                  al, 0x28
            //   f3a3????????         |                     
            //   b02a                 | mov                 al, 0x2a

        $sequence_1 = { 44 8a4100 047e 41 }
            // n = 4, score = 200
            //   44                   | inc                 esp
            //   8a4100               | mov                 al, byte ptr [ecx]
            //   047e                 | add                 al, 0x7e
            //   41                   | inc                 ecx

        $sequence_2 = { 00c0 c46c68ff 0808 008a34019ec5 6c 70ff }
            // n = 6, score = 200
            //   00c0                 | add                 al, al
            //   c46c68ff             | les                 ebp, ptr [eax + ebp*2 - 1]
            //   0808                 | or                  byte ptr [eax], cl
            //   008a34019ec5         | add                 byte ptr [edx - 0x3a61fecc], cl
            //   6c                   | insb                byte ptr es:[edi], dx
            //   70ff                 | jo                  1

        $sequence_3 = { 44 43 00dc 7442 000477 }
            // n = 5, score = 200
            //   44                   | inc                 esp
            //   43                   | inc                 ebx
            //   00dc                 | add                 ah, bl
            //   7442                 | je                  0x44
            //   000477               | add                 byte ptr [edi + esi*2], al

        $sequence_4 = { f3a3???????? b02a 57 366d ac 1988cc3127c8 }
            // n = 6, score = 200
            //   f3a3????????         |                     
            //   b02a                 | mov                 al, 0x2a
            //   57                   | push                edi
            //   366d                 | insd                dword ptr es:[edi], dx
            //   ac                   | lodsb               al, byte ptr [esi]
            //   1988cc3127c8         | sbb                 dword ptr [eax - 0x37d8ce34], ecx

        $sequence_5 = { 29c9 1a4201 c14cda0165 d347ac }
            // n = 4, score = 200
            //   29c9                 | sub                 ecx, ecx
            //   1a4201               | sbb                 al, byte ptr [edx + 1]
            //   c14cda0165           | ror                 dword ptr [edx + ebx*8 + 1], 0x65
            //   d347ac               | rol                 dword ptr [edi - 0x54], cl

        $sequence_6 = { 00f4 a1???????? 41 0094be4100d891 41 0084e84100a872 }
            // n = 6, score = 200
            //   00f4                 | add                 ah, dh
            //   a1????????           |                     
            //   41                   | inc                 ecx
            //   0094be4100d891       | add                 byte ptr [esi + edi*4 - 0x6e27ffbf], dl
            //   41                   | inc                 ecx
            //   0084e84100a872       | add                 byte ptr [eax + ebp*8 + 0x72a80041], al

        $sequence_7 = { 000d???????? 04f4 fd 0468 ff05???????? 000d???????? 04b8 }
            // n = 7, score = 200
            //   000d????????         |                     
            //   04f4                 | add                 al, 0xf4
            //   fd                   | std                 
            //   0468                 | add                 al, 0x68
            //   ff05????????         |                     
            //   000d????????         |                     
            //   04b8                 | add                 al, 0xb8

        $sequence_8 = { 00e8 dd7000 008bf98b5d1c 8d4de4 }
            // n = 4, score = 100
            //   00e8                 | add                 al, ch
            //   dd7000               | fnsave              dword ptr [eax]
            //   008bf98b5d1c         | add                 byte ptr [ebx + 0x1c5d8bf9], cl
            //   8d4de4               | lea                 ecx, [ebp - 0x1c]

        $sequence_9 = { 000f b681 fc b84500ff24 }
            // n = 4, score = 100
            //   000f                 | add                 byte ptr [edi], cl
            //   b681                 | mov                 dh, 0x81
            //   fc                   | cld                 
            //   b84500ff24           | mov                 eax, 0x24ff0045

        $sequence_10 = { 0108 8b442410 891e 894604 }
            // n = 4, score = 100
            //   0108                 | add                 dword ptr [eax], ecx
            //   8b442410             | mov                 eax, dword ptr [esp + 0x10]
            //   891e                 | mov                 dword ptr [esi], ebx
            //   894604               | mov                 dword ptr [esi + 4], eax

        $sequence_11 = { 00d1 6848007269 48 00856948008b }
            // n = 4, score = 100
            //   00d1                 | add                 cl, dl
            //   6848007269           | push                0x69720048
            //   48                   | dec                 eax
            //   00856948008b         | add                 byte ptr [ebp - 0x74ffb797], al

        $sequence_12 = { 00d1 6848004069 48 00d1 }
            // n = 4, score = 100
            //   00d1                 | add                 cl, dl
            //   6848004069           | push                0x69400048
            //   48                   | dec                 eax
            //   00d1                 | add                 cl, dl

        $sequence_13 = { 00856948008b ff558b ec 83ec0c }
            // n = 4, score = 100
            //   00856948008b         | add                 byte ptr [ebp - 0x74ffb797], al
            //   ff558b               | call                dword ptr [ebp - 0x75]
            //   ec                   | in                  al, dx
            //   83ec0c               | sub                 esp, 0xc

        $sequence_14 = { 00e8 f61c00 008bd9895df0 8b451c }
            // n = 4, score = 100
            //   00e8                 | add                 al, ch
            //   f61c00               | neg                 byte ptr [eax + eax]
            //   008bd9895df0         | add                 byte ptr [ebx - 0xfa27627], cl
            //   8b451c               | mov                 eax, dword ptr [ebp + 0x1c]

        $sequence_15 = { 0108 eb5a 8b4508 83ceff }
            // n = 4, score = 100
            //   0108                 | add                 dword ptr [eax], ecx
            //   eb5a                 | jmp                 0x5c
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   83ceff               | or                  esi, 0xffffffff

    condition:
        7 of them and filesize < 1867776
}

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*)
}