rule win_ismdoor_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        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 = "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 = { 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 = { e8???????? 48c785680200000f000000 4c89ad60020000 c6855002000000 4883bd0802000010 }
            // n = 5, score = 300
            //   e8????????           |                     
            //   48c785680200000f000000     | dec    eax
            //   4c89ad60020000       | sub                 esp, 0xc0
            //   c6855002000000       | dec                 eax
            //   4883bd0802000010     | mov                 dword ptr [ebp - 0x49], 0xfffffffe

        $sequence_2 = { e8???????? 488bf8 488d5570 488d8db0010000 }
            // n = 4, score = 300
            //   e8????????           |                     
            //   488bf8               | dec                 eax
            //   488d5570             | mov                 edi, eax
            //   488d8db0010000       | dec                 eax

        $sequence_3 = { 4157 488d68c1 4881ecc0000000 48c745b7feffffff 48895808 }
            // n = 5, score = 300
            //   4157                 | lea                 edx, [esp + 0x28]
            //   488d68c1             | dec                 eax
            //   4881ecc0000000       | mov                 ecx, ebx
            //   48c745b7feffffff     | call                dword ptr [eax + 0x38]
            //   48895808             | jmp                 0x1f

        $sequence_4 = { 668933 488b5c2450 488b742458 4883c430 }
            // n = 4, score = 300
            //   668933               | dec                 eax
            //   488b5c2450           | mov                 edx, ebx
            //   488b742458           | dec                 eax
            //   4883c430             | mov                 ecx, ebp

        $sequence_5 = { 483bf5 0f8c29ffffff 488d4b60 488d542428 }
            // n = 4, score = 300
            //   483bf5               | lea                 edx, [ebp + 0x70]
            //   0f8c29ffffff         | dec                 eax
            //   488d4b60             | lea                 ecx, [ebp + 0x1b0]
            //   488d542428           | dec                 eax

        $sequence_6 = { 488bcb ff5038 eb1a 488bd3 488bcd }
            // n = 5, score = 300
            //   488bcb               | cmp                 esi, ebp
            //   ff5038               | jl                  0xffffff2f
            //   eb1a                 | dec                 eax
            //   488bd3               | lea                 ecx, [ebx + 0x60]
            //   488bcd               | dec                 eax

        $sequence_7 = { e8???????? 894744 488b8c2488000000 4883c160 e8???????? 85c0 }
            // n = 6, score = 300
            //   e8????????           |                     
            //   894744               | inc                 ecx
            //   488b8c2488000000     | push                edi
            //   4883c160             | dec                 eax
            //   e8????????           |                     
            //   85c0                 | lea                 ebp, [eax - 0x3f]

        $sequence_8 = { 23c8 394b18 7709 d1ee 83c8ff }
            // n = 5, score = 100
            //   23c8                 | and                 ecx, eax
            //   394b18               | cmp                 dword ptr [ebx + 0x18], ecx
            //   7709                 | ja                  0xb
            //   d1ee                 | shr                 esi, 1
            //   83c8ff               | or                  eax, 0xffffffff

        $sequence_9 = { 8bf8 8bcc 8bf2 6a17 c741140f000000 c7411000000000 }
            // n = 6, score = 100
            //   8bf8                 | mov                 edi, eax
            //   8bcc                 | mov                 ecx, esp
            //   8bf2                 | mov                 esi, edx
            //   6a17                 | push                0x17
            //   c741140f000000       | mov                 dword ptr [ecx + 0x14], 0xf
            //   c7411000000000       | mov                 dword ptr [ecx + 0x10], 0

        $sequence_10 = { 8b4594 83e001 0f840c000000 836594fe 8b4d9c e9???????? }
            // n = 6, score = 100
            //   8b4594               | mov                 eax, dword ptr [ebp - 0x6c]
            //   83e001               | and                 eax, 1
            //   0f840c000000         | je                  0x12
            //   836594fe             | and                 dword ptr [ebp - 0x6c], 0xfffffffe
            //   8b4d9c               | mov                 ecx, dword ptr [ebp - 0x64]
            //   e9????????           |                     

        $sequence_11 = { 8bf0 b9???????? c645fc01 e8???????? 52 }
            // n = 5, score = 100
            //   8bf0                 | mov                 esi, eax
            //   b9????????           |                     
            //   c645fc01             | mov                 byte ptr [ebp - 4], 1
            //   e8????????           |                     
            //   52                   | push                edx

        $sequence_12 = { 897dd4 85ff 752a 8b55e8 837a1410 }
            // n = 5, score = 100
            //   897dd4               | mov                 dword ptr [ebp - 0x2c], edi
            //   85ff                 | test                edi, edi
            //   752a                 | jne                 0x2c
            //   8b55e8               | mov                 edx, dword ptr [ebp - 0x18]
            //   837a1410             | cmp                 dword ptr [edx + 0x14], 0x10

        $sequence_13 = { 33db 660fd6442478 c784248000000000000000 895c2478 }
            // n = 4, score = 100
            //   33db                 | xor                 ebx, ebx
            //   660fd6442478         | movq                qword ptr [esp + 0x78], xmm0
            //   c784248000000000000000     | mov    dword ptr [esp + 0x80], 0
            //   895c2478             | mov                 dword ptr [esp + 0x78], ebx

        $sequence_14 = { e8???????? 8d8dc8fdffff e8???????? 83c418 8bc8 6a02 }
            // n = 6, score = 100
            //   e8????????           |                     
            //   8d8dc8fdffff         | lea                 ecx, [ebp - 0x238]
            //   e8????????           |                     
            //   83c418               | add                 esp, 0x18
            //   8bc8                 | mov                 ecx, eax
            //   6a02                 | push                2

    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
}