rule win_ufrstealer_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.ufrstealer."
        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.ufrstealer"
        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 = { 8b45e4 ff30 68???????? 68???????? ff15???????? 83c40c }
            // n = 6, score = 200
            //   8b45e4               | mov                 eax, dword ptr [ebp - 0x1c]
            //   ff30                 | push                dword ptr [eax]
            //   68????????           |                     
            //   68????????           |                     
            //   ff15????????         |                     
            //   83c40c               | add                 esp, 0xc

        $sequence_1 = { 8bc8 8d8500f4ffff 48 03c1 80383a 7505 c60000 }
            // n = 7, score = 200
            //   8bc8                 | mov                 ecx, eax
            //   8d8500f4ffff         | lea                 eax, [ebp - 0xc00]
            //   48                   | dec                 eax
            //   03c1                 | add                 eax, ecx
            //   80383a               | cmp                 byte ptr [eax], 0x3a
            //   7505                 | jne                 7
            //   c60000               | mov                 byte ptr [eax], 0

        $sequence_2 = { 40 3bc7 72f2 eb1e 8b75e8 46 8975e8 }
            // n = 7, score = 200
            //   40                   | inc                 eax
            //   3bc7                 | cmp                 eax, edi
            //   72f2                 | jb                  0xfffffff4
            //   eb1e                 | jmp                 0x20
            //   8b75e8               | mov                 esi, dword ptr [ebp - 0x18]
            //   46                   | inc                 esi
            //   8975e8               | mov                 dword ptr [ebp - 0x18], esi

        $sequence_3 = { b9???????? 800408fb 40 3bc7 }
            // n = 4, score = 200
            //   b9????????           |                     
            //   800408fb             | add                 byte ptr [eax + ecx], 0xfb
            //   40                   | inc                 eax
            //   3bc7                 | cmp                 eax, edi

        $sequence_4 = { 8b4df4 c1e902 51 8b048d6c9a4200 8945f8 ff75f8 6a00 }
            // n = 7, score = 200
            //   8b4df4               | mov                 ecx, dword ptr [ebp - 0xc]
            //   c1e902               | shr                 ecx, 2
            //   51                   | push                ecx
            //   8b048d6c9a4200       | mov                 eax, dword ptr [ecx*4 + 0x429a6c]
            //   8945f8               | mov                 dword ptr [ebp - 8], eax
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   6a00                 | push                0

        $sequence_5 = { 894df8 ff75f8 ff15???????? 50 }
            // n = 4, score = 200
            //   894df8               | mov                 dword ptr [ebp - 8], ecx
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   ff15????????         |                     
            //   50                   | push                eax

        $sequence_6 = { ff75f4 ff75f8 ff15???????? 6a00 6a00 6a00 ff75f8 }
            // n = 7, score = 200
            //   ff75f4               | push                dword ptr [ebp - 0xc]
            //   ff75f8               | push                dword ptr [ebp - 8]
            //   ff15????????         |                     
            //   6a00                 | push                0
            //   6a00                 | push                0
            //   6a00                 | push                0
            //   ff75f8               | push                dword ptr [ebp - 8]

        $sequence_7 = { 68???????? 6a04 8d45d8 50 ff35???????? ff15???????? }
            // n = 6, score = 200
            //   68????????           |                     
            //   6a04                 | push                4
            //   8d45d8               | lea                 eax, [ebp - 0x28]
            //   50                   | push                eax
            //   ff35????????         |                     
            //   ff15????????         |                     

        $sequence_8 = { 68???????? e8???????? 8305????????02 6a02 68???????? e8???????? 8305????????02 }
            // n = 7, score = 200
            //   68????????           |                     
            //   e8????????           |                     
            //   8305????????02       |                     
            //   6a02                 | push                2
            //   68????????           |                     
            //   e8????????           |                     
            //   8305????????02       |                     

        $sequence_9 = { 0f8443e7ffff a3???????? 68???????? ff35???????? ff15???????? 85c0 0f8425e7ffff }
            // n = 7, score = 200
            //   0f8443e7ffff         | je                  0xffffe749
            //   a3????????           |                     
            //   68????????           |                     
            //   ff35????????         |                     
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   0f8425e7ffff         | je                  0xffffe72b

    condition:
        7 of them and filesize < 770048
}