rule win_fast_pos_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.fast_pos."
        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.fast_pos"
        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 = { 81feffffff7f 7ecf eb33 8b49f0 85c9 7409 }
            // n = 6, score = 1000
            //   81feffffff7f         | cmp                 esi, 0x7fffffff
            //   7ecf                 | jle                 0xffffffd1
            //   eb33                 | jmp                 0x35
            //   8b49f0               | mov                 ecx, dword ptr [ecx - 0x10]
            //   85c9                 | test                ecx, ecx
            //   7409                 | je                  0xb

        $sequence_1 = { 50 89b578ffffff c7857cffffff00000000 ff15???????? 85c0 8d45e4 }
            // n = 6, score = 1000
            //   50                   | push                eax
            //   89b578ffffff         | mov                 dword ptr [ebp - 0x88], esi
            //   c7857cffffff00000000     | mov    dword ptr [ebp - 0x84], 0
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   8d45e4               | lea                 eax, [ebp - 0x1c]

        $sequence_2 = { 85c0 8d45e4 7407 68???????? }
            // n = 4, score = 1000
            //   85c0                 | test                eax, eax
            //   8d45e4               | lea                 eax, [ebp - 0x1c]
            //   7407                 | je                  9
            //   68????????           |                     

        $sequence_3 = { 7427 8b46f4 894704 8d4710 8b4ef4 41 51 }
            // n = 7, score = 1000
            //   7427                 | je                  0x29
            //   8b46f4               | mov                 eax, dword ptr [esi - 0xc]
            //   894704               | mov                 dword ptr [edi + 4], eax
            //   8d4710               | lea                 eax, [edi + 0x10]
            //   8b4ef4               | mov                 ecx, dword ptr [esi - 0xc]
            //   41                   | inc                 ecx
            //   51                   | push                ecx

        $sequence_4 = { 6a64 8d4580 c745fc00000000 50 89b578ffffff c7857cffffff00000000 ff15???????? }
            // n = 7, score = 1000
            //   6a64                 | push                0x64
            //   8d4580               | lea                 eax, [ebp - 0x80]
            //   c745fc00000000       | mov                 dword ptr [ebp - 4], 0
            //   50                   | push                eax
            //   89b578ffffff         | mov                 dword ptr [ebp - 0x88], esi
            //   c7857cffffff00000000     | mov    dword ptr [ebp - 0x84], 0
            //   ff15????????         |                     

        $sequence_5 = { 68???????? 50 e8???????? 8b75f0 83c410 }
            // n = 5, score = 1000
            //   68????????           |                     
            //   50                   | push                eax
            //   e8????????           |                     
            //   8b75f0               | mov                 esi, dword ptr [ebp - 0x10]
            //   83c410               | add                 esp, 0x10

        $sequence_6 = { c645fc08 ff15???????? 50 ff36 }
            // n = 4, score = 1000
            //   c645fc08             | mov                 byte ptr [ebp - 4], 8
            //   ff15????????         |                     
            //   50                   | push                eax
            //   ff36                 | push                dword ptr [esi]

        $sequence_7 = { 8d56fc 8bc8 7c1f 3b4ef0 751a }
            // n = 5, score = 1000
            //   8d56fc               | lea                 edx, [esi - 4]
            //   8bc8                 | mov                 ecx, eax
            //   7c1f                 | jl                  0x21
            //   3b4ef0               | cmp                 ecx, dword ptr [esi - 0x10]
            //   751a                 | jne                 0x1c

        $sequence_8 = { 8be5 5d c20c00 81feffffff7f 7ecf }
            // n = 5, score = 1000
            //   8be5                 | mov                 esp, ebp
            //   5d                   | pop                 ebp
            //   c20c00               | ret                 0xc
            //   81feffffff7f         | cmp                 esi, 0x7fffffff
            //   7ecf                 | jle                 0xffffffd1

        $sequence_9 = { ff36 ff30 e8???????? 8b95e4feffff }
            // n = 4, score = 1000
            //   ff36                 | push                dword ptr [esi]
            //   ff30                 | push                dword ptr [eax]
            //   e8????????           |                     
            //   8b95e4feffff         | mov                 edx, dword ptr [ebp - 0x11c]

    condition:
        7 of them and filesize < 327680
}