rule win_former_first_rat_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.former_first_rat."
        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.former_first_rat"
        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 = { 57 e8???????? 83c404 56 e8???????? 8b8504ffffff 83c404 }
            // n = 7, score = 200
            //   57                   | push                edi
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   56                   | push                esi
            //   e8????????           |                     
            //   8b8504ffffff         | mov                 eax, dword ptr [ebp - 0xfc]
            //   83c404               | add                 esp, 4

        $sequence_1 = { 75f8 8d85b4feffff 68???????? b90d000000 be???????? 50 }
            // n = 6, score = 200
            //   75f8                 | jne                 0xfffffffa
            //   8d85b4feffff         | lea                 eax, [ebp - 0x14c]
            //   68????????           |                     
            //   b90d000000           | mov                 ecx, 0xd
            //   be????????           |                     
            //   50                   | push                eax

        $sequence_2 = { b93c000000 03ce 83c40c c74424241c000000 81f900100000 7e5a }
            // n = 6, score = 200
            //   b93c000000           | mov                 ecx, 0x3c
            //   03ce                 | add                 ecx, esi
            //   83c40c               | add                 esp, 0xc
            //   c74424241c000000     | mov                 dword ptr [esp + 0x24], 0x1c
            //   81f900100000         | cmp                 ecx, 0x1000
            //   7e5a                 | jle                 0x5c

        $sequence_3 = { 81c208020000 f3a5 3b44240c 75e4 }
            // n = 4, score = 200
            //   81c208020000         | add                 edx, 0x208
            //   f3a5                 | rep movsd           dword ptr es:[edi], dword ptr [esi]
            //   3b44240c             | cmp                 eax, dword ptr [esp + 0xc]
            //   75e4                 | jne                 0xffffffe6

        $sequence_4 = { 2bf1 b87fe0077e f7ee c1fa08 8bf2 }
            // n = 5, score = 200
            //   2bf1                 | sub                 esi, ecx
            //   b87fe0077e           | mov                 eax, 0x7e07e07f
            //   f7ee                 | imul                esi
            //   c1fa08               | sar                 edx, 8
            //   8bf2                 | mov                 esi, edx

        $sequence_5 = { 740a c705????????05000000 6a59 ffd6 }
            // n = 4, score = 200
            //   740a                 | je                  0xc
            //   c705????????05000000     |     
            //   6a59                 | push                0x59
            //   ffd6                 | call                esi

        $sequence_6 = { 8d8de0feffff 51 bb08000000 e8???????? 8b9df8feffff 57 e8???????? }
            // n = 7, score = 200
            //   8d8de0feffff         | lea                 ecx, [ebp - 0x120]
            //   51                   | push                ecx
            //   bb08000000           | mov                 ebx, 8
            //   e8????????           |                     
            //   8b9df8feffff         | mov                 ebx, dword ptr [ebp - 0x108]
            //   57                   | push                edi
            //   e8????????           |                     

        $sequence_7 = { 6a00 50 c645b400 e8???????? 33c0 }
            // n = 5, score = 200
            //   6a00                 | push                0
            //   50                   | push                eax
            //   c645b400             | mov                 byte ptr [ebp - 0x4c], 0
            //   e8????????           |                     
            //   33c0                 | xor                 eax, eax

        $sequence_8 = { 488d4c2438 e8???????? 488bd0 488d8c24f0000000 }
            // n = 4, score = 100
            //   488d4c2438           | dec                 ebp
            //   e8????????           |                     
            //   488bd0               | arpl                word ptr [eax + 4], cx
            //   488d8c24f0000000     | dec                 ebp

        $sequence_9 = { 4889040a 488b01 48637004 4803f1 }
            // n = 4, score = 100
            //   4889040a             | dec                 eax
            //   488b01               | and                 dword ptr [esp + 0x98], 0
            //   48637004             | mov                 byte ptr [esp + 0x88], 0
            //   4803f1               | cmp                 byte ptr [esp + 0x128], 0

        $sequence_10 = { 4d634804 4d8b6c3928 4d85ed 7e0a }
            // n = 4, score = 100
            //   4d634804             | dec                 esp
            //   4d8b6c3928           | mov                 dword ptr [esp + 0x148], edi
            //   4d85ed               | dec                 esp
            //   7e0a                 | mov                 dword ptr [esp + 0x150], edi

        $sequence_11 = { 4883f8ff 0f851e010000 488d158de00100 488bcf 498bf6 }
            // n = 5, score = 100
            //   4883f8ff             | dec                 ecx
            //   0f851e010000         | mov                 ecx, dword ptr [ecx]
            //   488d158de00100       | jmp                 8
            //   488bcf               | dec                 eax
            //   498bf6               | mov                 dword ptr [esp + 0xa0], 0xf

        $sequence_12 = { 4883792008 7205 498b09 eb03 }
            // n = 4, score = 100
            //   4883792008           | mov                 ebp, dword ptr [ecx + edi + 0x28]
            //   7205                 | dec                 ebp
            //   498b09               | test                ebp, ebp
            //   eb03                 | jle                 0xf

        $sequence_13 = { 498bc7 4889842430010000 4c89bc2448010000 4c89bc2450010000 }
            // n = 4, score = 100
            //   498bc7               | dec                 ecx
            //   4889842430010000     | mov                 eax, edi
            //   4c89bc2448010000     | dec                 eax
            //   4c89bc2450010000     | mov                 dword ptr [esp + 0x130], eax

        $sequence_14 = { 48c78424a00000000f000000 4883a4249800000000 c684248800000000 80bc242801000000 743a }
            // n = 5, score = 100
            //   48c78424a00000000f000000     | dec    eax
            //   4883a4249800000000     | lea    ecx, [esp + 0x38]
            //   c684248800000000     | dec                 eax
            //   80bc242801000000     | mov                 edx, eax
            //   743a                 | dec                 eax

        $sequence_15 = { 4c8da1f4010000 41383c24 7440 33d2 }
            // n = 4, score = 100
            //   4c8da1f4010000       | lea                 ecx, [esp + 0xf0]
            //   41383c24             | dec                 eax
            //   7440                 | cmp                 dword ptr [ecx + 0x20], 8
            //   33d2                 | jb                  0xc

    condition:
        7 of them and filesize < 626688
}