rule win_mofksys_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.mofksys."
        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.mofksys"
        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 = { ff15???????? c7859cfaffff60e04200 eb0a c7859cfaffff60e04200 8b859cfaffff 8b08 8b959cfaffff }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   c7859cfaffff60e04200     | mov    dword ptr [ebp - 0x564], 0x42e060
            //   eb0a                 | jmp                 0xc
            //   c7859cfaffff60e04200     | mov    dword ptr [ebp - 0x564], 0x42e060
            //   8b859cfaffff         | mov                 eax, dword ptr [ebp - 0x564]
            //   8b08                 | mov                 ecx, dword ptr [eax]
            //   8b959cfaffff         | mov                 edx, dword ptr [ebp - 0x564]

        $sequence_1 = { 50 8b45d8 50 e8???????? 898540fdffff ff15???????? 8d8d00fcffff }
            // n = 7, score = 100
            //   50                   | push                eax
            //   8b45d8               | mov                 eax, dword ptr [ebp - 0x28]
            //   50                   | push                eax
            //   e8????????           |                     
            //   898540fdffff         | mov                 dword ptr [ebp - 0x2c0], eax
            //   ff15????????         |                     
            //   8d8d00fcffff         | lea                 ecx, [ebp - 0x400]

        $sequence_2 = { 8bf8 8b07 8b4d10 8b11 6bd20f }
            // n = 5, score = 100
            //   8bf8                 | mov                 edi, eax
            //   8b07                 | mov                 eax, dword ptr [edi]
            //   8b4d10               | mov                 ecx, dword ptr [ebp + 0x10]
            //   8b11                 | mov                 edx, dword ptr [ecx]
            //   6bd20f               | imul                edx, edx, 0xf

        $sequence_3 = { beff0f0000 2bf2 3bf0 7208 ffd3 8b0d???????? 8bc6 }
            // n = 7, score = 100
            //   beff0f0000           | mov                 esi, 0xfff
            //   2bf2                 | sub                 esi, edx
            //   3bf0                 | cmp                 esi, eax
            //   7208                 | jb                  0xa
            //   ffd3                 | call                ebx
            //   8b0d????????         |                     
            //   8bc6                 | mov                 eax, esi

        $sequence_4 = { ff15???????? 8b55b8 89951cffffff c745b800000000 6a00 6aff 8d45a8 }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   8b55b8               | mov                 edx, dword ptr [ebp - 0x48]
            //   89951cffffff         | mov                 dword ptr [ebp - 0xe4], edx
            //   c745b800000000       | mov                 dword ptr [ebp - 0x48], 0
            //   6a00                 | push                0
            //   6aff                 | push                -1
            //   8d45a8               | lea                 eax, [ebp - 0x58]

        $sequence_5 = { 8d5594 52 ff15???????? 8b4d94 85c9 7426 66833901 }
            // n = 7, score = 100
            //   8d5594               | lea                 edx, [ebp - 0x6c]
            //   52                   | push                edx
            //   ff15????????         |                     
            //   8b4d94               | mov                 ecx, dword ptr [ebp - 0x6c]
            //   85c9                 | test                ecx, ecx
            //   7426                 | je                  0x28
            //   66833901             | cmp                 word ptr [ecx], 1

        $sequence_6 = { ff15???????? c745fc13000000 ff15???????? 8945c4 c745bc08000000 8d55bc 52 }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   c745fc13000000       | mov                 dword ptr [ebp - 4], 0x13
            //   ff15????????         |                     
            //   8945c4               | mov                 dword ptr [ebp - 0x3c], eax
            //   c745bc08000000       | mov                 dword ptr [ebp - 0x44], 8
            //   8d55bc               | lea                 edx, [ebp - 0x44]
            //   52                   | push                edx

        $sequence_7 = { 8bd0 8d4dd0 ffd6 8d459c 8d4da0 50 8d55a4 }
            // n = 7, score = 100
            //   8bd0                 | mov                 edx, eax
            //   8d4dd0               | lea                 ecx, [ebp - 0x30]
            //   ffd6                 | call                esi
            //   8d459c               | lea                 eax, [ebp - 0x64]
            //   8d4da0               | lea                 ecx, [ebp - 0x60]
            //   50                   | push                eax
            //   8d55a4               | lea                 edx, [ebp - 0x5c]

        $sequence_8 = { ff15???????? 83bd40fdffff00 0f8595f8ffff c745fc3a000000 8b4dd8 51 e8???????? }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   83bd40fdffff00       | cmp                 dword ptr [ebp - 0x2c0], 0
            //   0f8595f8ffff         | jne                 0xfffff89b
            //   c745fc3a000000       | mov                 dword ptr [ebp - 4], 0x3a
            //   8b4dd8               | mov                 ecx, dword ptr [ebp - 0x28]
            //   51                   | push                ecx
            //   e8????????           |                     

        $sequence_9 = { e9???????? 668b8558f8ffff 6603c2 0f80e50f0000 8bd0 899508fdffff e9???????? }
            // n = 7, score = 100
            //   e9????????           |                     
            //   668b8558f8ffff       | mov                 ax, word ptr [ebp - 0x7a8]
            //   6603c2               | add                 ax, dx
            //   0f80e50f0000         | jo                  0xfeb
            //   8bd0                 | mov                 edx, eax
            //   899508fdffff         | mov                 dword ptr [ebp - 0x2f8], edx
            //   e9????????           |                     

    condition:
        7 of them and filesize < 401408
}