rule win_ismdoor_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.ismdoor."
        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.ismdoor"
        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 = { 83f8ff 7504 32c0 eb05 c0e804 2401 84c0 }
            // n = 7, score = 400
            //   83f8ff               | cmp                 eax, -1
            //   7504                 | jne                 6
            //   32c0                 | xor                 al, al
            //   eb05                 | jmp                 7
            //   c0e804               | shr                 al, 4
            //   2401                 | and                 al, 1
            //   84c0                 | test                al, al

        $sequence_1 = { 488b4f70 e8???????? 488b4f68 e8???????? 90 }
            // n = 5, score = 300
            //   488b4f70             | dec                 esp
            //   e8????????           |                     
            //   488b4f68             | lea                 eax, [ebp + 0xb0]
            //   e8????????           |                     
            //   90                   | dec                 eax

        $sequence_2 = { cc 48ffc2 e8???????? 488bf0 33ff 48897c2438 }
            // n = 6, score = 300
            //   cc                   | jne                 0x57
            //   48ffc2               | dec                 ebp
            //   e8????????           |                     
            //   488bf0               | test                esi, esi
            //   33ff                 | je                  0x57
            //   48897c2438           | nop                 

        $sequence_3 = { 48895c2440 eb98 85ff 7532 }
            // n = 4, score = 300
            //   48895c2440           | sub                 esp, 0x20
            //   eb98                 | cmp                 byte ptr [ecx + 0x610], 0
            //   85ff                 | dec                 eax
            //   7532                 | mov                 ebx, ecx

        $sequence_4 = { e8???????? 90 4c8d85b0000000 4883bdc800000010 4c0f4385b0000000 }
            // n = 5, score = 300
            //   e8????????           |                     
            //   90                   | jne                 0x38
            //   4c8d85b0000000       | cmp                 dword ptr [ebx + 0x80], 0
            //   4883bdc800000010     | dec                 eax
            //   4c0f4385b0000000     | mov                 dword ptr [ebx + 0x18], eax

        $sequence_5 = { 4c897c2430 44887c2420 48837c245810 720a }
            // n = 4, score = 300
            //   4c897c2430           | dec                 esp
            //   44887c2420           | mov                 dword ptr [esp + 0x30], edi
            //   48837c245810         | inc                 esp
            //   720a                 | mov                 byte ptr [esp + 0x20], bh

        $sequence_6 = { 4883ec20 80b91006000000 488bd9 7407 f0ff0d???????? }
            // n = 5, score = 300
            //   4883ec20             | dec                 eax
            //   80b91006000000       | cmp                 dword ptr [esp + 0x58], 0x10
            //   488bd9               | jb                  0xc
            //   7407                 | dec                 eax
            //   f0ff0d????????       |                     

        $sequence_7 = { 83bb8000000000 48894318 7551 4d85f6 744c }
            // n = 5, score = 300
            //   83bb8000000000       | je                  0x13
            //   48894318             | dec                 eax
            //   7551                 | mov                 dword ptr [esp + 0x40], ebx
            //   4d85f6               | jmp                 0xffffff9a
            //   744c                 | test                edi, edi

        $sequence_8 = { 8b4004 c74430902cb84700 8b4690 8b4804 }
            // n = 4, score = 100
            //   8b4004               | mov                 eax, dword ptr [eax + 4]
            //   c74430902cb84700     | mov                 dword ptr [eax + esi - 0x70], 0x47b82c
            //   8b4690               | mov                 eax, dword ptr [esi - 0x70]
            //   8b4804               | mov                 ecx, dword ptr [eax + 4]

        $sequence_9 = { 0f84110e0000 8b8d68ffffff b8abaaaa2a 8bb564ffffff }
            // n = 4, score = 100
            //   0f84110e0000         | je                  0xe17
            //   8b8d68ffffff         | mov                 ecx, dword ptr [ebp - 0x98]
            //   b8abaaaa2a           | mov                 eax, 0x2aaaaaab
            //   8bb564ffffff         | mov                 esi, dword ptr [ebp - 0x9c]

        $sequence_10 = { e8???????? 83c404 eb03 8b7730 }
            // n = 4, score = 100
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   eb03                 | jmp                 5
            //   8b7730               | mov                 esi, dword ptr [edi + 0x30]

        $sequence_11 = { 83ec18 c645fc0d 8bcc 8d459c 6aff }
            // n = 5, score = 100
            //   83ec18               | sub                 esp, 0x18
            //   c645fc0d             | mov                 byte ptr [ebp - 4], 0xd
            //   8bcc                 | mov                 ecx, esp
            //   8d459c               | lea                 eax, [ebp - 0x64]
            //   6aff                 | push                -1

        $sequence_12 = { 7415 8965d0 6aff 50 }
            // n = 4, score = 100
            //   7415                 | je                  0x17
            //   8965d0               | mov                 dword ptr [ebp - 0x30], esp
            //   6aff                 | push                -1
            //   50                   | push                eax

        $sequence_13 = { 668901 8d4508 50 e8???????? c645fc34 }
            // n = 5, score = 100
            //   668901               | mov                 word ptr [ecx], ax
            //   8d4508               | lea                 eax, [ebp + 8]
            //   50                   | push                eax
            //   e8????????           |                     
            //   c645fc34             | mov                 byte ptr [ebp - 4], 0x34

        $sequence_14 = { 8d9b00000000 6a04 6a00 68???????? 8d4d08 e8???????? }
            // n = 6, score = 100
            //   8d9b00000000         | lea                 ebx, [ebx]
            //   6a04                 | push                4
            //   6a00                 | push                0
            //   68????????           |                     
            //   8d4d08               | lea                 ecx, [ebp + 8]
            //   e8????????           |                     

    condition:
        7 of them and filesize < 1933312
}

rule win_ismdoor_w0 {
	meta:
        author = "Florian Roth"
        reference = "https://goo.gl/urp4CD"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.ismdoor"
        malpedia_version = "20180301"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
    strings:
        $x1 = "cmd /u /c WMIC /Node:localhost /Namespace:\\\\root\\SecurityCenter" fullword ascii
        $x2 = "cmd /a /c net user administrator /domain >>" fullword ascii
        $x3 = "cmd /a /c netstat -ant >>\"%localappdata%\\Microsoft\\" fullword ascii
        $o1 = "========================== (Net User) ==========================" ascii fullword
    condition:
        1 of them
}