rule win_udpos_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.udpos."
        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.udpos"
        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 = { ffd6 c705????????01000000 68fe010000 53 68???????? }
            // n = 5, score = 100
            //   ffd6                 | call                esi
            //   c705????????01000000     |     
            //   68fe010000           | push                0x1fe
            //   53                   | push                ebx
            //   68????????           |                     

        $sequence_1 = { 6a00 50 e8???????? 6a29 8d8d6cffffff 6a00 51 }
            // n = 7, score = 100
            //   6a00                 | push                0
            //   50                   | push                eax
            //   e8????????           |                     
            //   6a29                 | push                0x29
            //   8d8d6cffffff         | lea                 ecx, [ebp - 0x94]
            //   6a00                 | push                0
            //   51                   | push                ecx

        $sequence_2 = { 0f841a010000 8d85d4fbffff 50 8d8ddcfbffff 51 }
            // n = 5, score = 100
            //   0f841a010000         | je                  0x120
            //   8d85d4fbffff         | lea                 eax, [ebp - 0x42c]
            //   50                   | push                eax
            //   8d8ddcfbffff         | lea                 ecx, [ebp - 0x424]
            //   51                   | push                ecx

        $sequence_3 = { 8a4c0df0 4e 880e 8bc8 }
            // n = 4, score = 100
            //   8a4c0df0             | mov                 cl, byte ptr [ebp + ecx - 0x10]
            //   4e                   | dec                 esi
            //   880e                 | mov                 byte ptr [esi], cl
            //   8bc8                 | mov                 ecx, eax

        $sequence_4 = { 8b8da4feffff 88540101 79da 8b4dfc 33cd e8???????? 8be5 }
            // n = 7, score = 100
            //   8b8da4feffff         | mov                 ecx, dword ptr [ebp - 0x15c]
            //   88540101             | mov                 byte ptr [ecx + eax + 1], dl
            //   79da                 | jns                 0xffffffdc
            //   8b4dfc               | mov                 ecx, dword ptr [ebp - 4]
            //   33cd                 | xor                 ecx, ebp
            //   e8????????           |                     
            //   8be5                 | mov                 esp, ebp

        $sequence_5 = { b903000000 2bcf 0fb63c06 03c9 03c9 }
            // n = 5, score = 100
            //   b903000000           | mov                 ecx, 3
            //   2bcf                 | sub                 ecx, edi
            //   0fb63c06             | movzx               edi, byte ptr [esi + eax]
            //   03c9                 | add                 ecx, ecx
            //   03c9                 | add                 ecx, ecx

        $sequence_6 = { 8bff 660fbe1431 6689944d5cf5ffff 41 3bc8 7cee 33c9 }
            // n = 7, score = 100
            //   8bff                 | mov                 edi, edi
            //   660fbe1431           | movsx               dx, byte ptr [ecx + esi]
            //   6689944d5cf5ffff     | mov                 word ptr [ebp + ecx*2 - 0xaa4], dx
            //   41                   | inc                 ecx
            //   3bc8                 | cmp                 ecx, eax
            //   7cee                 | jl                  0xfffffff0
            //   33c9                 | xor                 ecx, ecx

        $sequence_7 = { 3bc8 7cee 33c9 6a64 51 8d95b4f7ffff 52 }
            // n = 7, score = 100
            //   3bc8                 | cmp                 ecx, eax
            //   7cee                 | jl                  0xfffffff0
            //   33c9                 | xor                 ecx, ecx
            //   6a64                 | push                0x64
            //   51                   | push                ecx
            //   8d95b4f7ffff         | lea                 edx, [ebp - 0x84c]
            //   52                   | push                edx

        $sequence_8 = { 53 e8???????? 83c404 8b95e4fbffff 52 ff15???????? 5b }
            // n = 7, score = 100
            //   53                   | push                ebx
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   8b95e4fbffff         | mov                 edx, dword ptr [ebp - 0x41c]
            //   52                   | push                edx
            //   ff15????????         |                     
            //   5b                   | pop                 ebx

        $sequence_9 = { 3bc3 7443 68???????? 899dc4fbffff }
            // n = 4, score = 100
            //   3bc3                 | cmp                 eax, ebx
            //   7443                 | je                  0x45
            //   68????????           |                     
            //   899dc4fbffff         | mov                 dword ptr [ebp - 0x43c], ebx

    condition:
        7 of them and filesize < 163840
}