rule win_akira_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.akira."
        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.akira"
        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 = { b990030000 e8???????? 89ac24f8030000 488d8c2410040000 48894c2430 4889742428 48895c2420 }
            // n = 7, score = 200
            //   b990030000           | mov                 byte ptr [ebp + 0x282], 0x72
            //   e8????????           |                     
            //   89ac24f8030000       | nop                 
            //   488d8c2410040000     | mov                 byte ptr [ebp + 0x27d], 0
            //   48894c2430           | mov                 byte ptr [ebp + 0x27e], 0x6a
            //   4889742428           | mov                 byte ptr [ebp + 0x27f], 0xa
            //   48895c2420           | mov                 byte ptr [ebp + 0x280], 0x60

        $sequence_1 = { 6690 488d42fe 0fb708 6683f95c 740e 6683f92f 7408 }
            // n = 7, score = 200
            //   6690                 | inc                 eax
            //   488d42fe             | push                ebx
            //   0fb708               | dec                 eax
            //   6683f95c             | sub                 esp, 0x20
            //   740e                 | mov                 ebx, ecx
            //   6683f92f             | dec                 esp
            //   7408                 | lea                 ecx, [0x27491]

        $sequence_2 = { 4032f6 4084f6 7409 488bcf ff15???????? 488b5c2440 488b6c2448 }
            // n = 7, score = 200
            //   4032f6               | dec                 esp
            //   4084f6               | mov                 dword ptr [edi + 0x388], edi
            //   7409                 | dec                 ecx
            //   488bcf               | mov                 dword ptr [edi + 0x10], ebx
            //   ff15????????         |                     
            //   488b5c2440           | dec                 ecx
            //   488b6c2448           | lea                 ecx, [edi + 0x18]

        $sequence_3 = { 90 66837f0a00 7410 ba90030000 488bcf e8???????? }
            // n = 6, score = 200
            //   90                   | dec                 eax
            //   66837f0a00           | mov                 ecx, eax
            //   7410                 | call                dword ptr [eax + 8]
            //   ba90030000           | nop                 
            //   488bcf               | dec                 eax
            //   e8????????           |                     

        $sequence_4 = { 4889457f 4885db 743c 660f1f840000000000 488d45bf 4889442420 4c8d4d7f }
            // n = 7, score = 200
            //   4889457f             | dec                 eax
            //   4885db               | cmp                 eax, 0x1f
            //   743c                 | ja                  0x13e1
            //   660f1f840000000000     | xorps    xmm0, xmm0
            //   488d45bf             | movdqu              xmmword ptr [ebp - 0x40], xmm0
            //   4889442420           | dec                 esp
            //   4c8d4d7f             | mov                 dword ptr [ebp - 0x30], ebp

        $sequence_5 = { 8bd8 83f8ff 756f 48897c2440 ff15???????? 65488b0c2558000000 8bf8 }
            // n = 7, score = 200
            //   8bd8                 | dec                 eax
            //   83f8ff               | lea                 ecx, [0x4c7cc]
            //   756f                 | jmp                 0x130a
            //   48897c2440           | dec                 eax
            //   ff15????????         |                     
            //   65488b0c2558000000     | lea    ecx, [0x4c7c3]
            //   8bf8                 | and                 ecx, 0x3f

        $sequence_6 = { 0f57c0 0f118550020000 0f57c9 660f7f8d60020000 488d458d 4c8bc3 0f1f00 }
            // n = 7, score = 200
            //   0f57c0               | dec                 ebp
            //   0f118550020000       | lea                 edx, [edx + 1]
            //   0f57c9               | sub                 ecx, 0x5b
            //   660f7f8d60020000     | mov                 eax, 0x81020409
            //   488d458d             | inc                 esp
            //   4c8bc3               | imul                eax, ecx, 0x33
            //   0f1f00               | inc                 ecx

        $sequence_7 = { e8???????? 498d4601 803800 4c0f4ff0 410fb60e 80f97f 0f8553ffffff }
            // n = 7, score = 200
            //   e8????????           |                     
            //   498d4601             | mov                 byte ptr [ebp + 0xeb], 0x21
            //   803800               | mov                 byte ptr [ebp + 0xec], 0x10
            //   4c0f4ff0             | mov                 byte ptr [ebp + 0xed], 0x2e
            //   410fb60e             | mov                 byte ptr [ebp + 0xee], 0x10
            //   80f97f               | mov                 byte ptr [ebp + 0xef], 0x10
            //   0f8553ffffff         | mov                 byte ptr [ebp + 0xf0], 0x10

        $sequence_8 = { 75b4 eb4e 897567 4889757f 4889756f 8b4740 89442420 }
            // n = 7, score = 200
            //   75b4                 | movups              xmmword ptr [ebp + 0xae0], xmm0
            //   eb4e                 | xorps               xmm1, xmm1
            //   897567               | movdqa              xmmword ptr [ebp + 0xaf0], xmm1
            //   4889757f             | dec                 eax
            //   4889756f             | lea                 eax, [ebp + 0xb]
            //   8b4740               | dec                 esp
            //   89442420             | mov                 eax, edi

        $sequence_9 = { 75e8 4983c002 4d3bc3 7429 410fb700 6683f85c 7406 }
            // n = 7, score = 200
            //   75e8                 | movdqa              xmmword ptr [ebp + 0xb50], xmm1
            //   4983c002             | dec                 eax
            //   4d3bc3               | lea                 eax, [ebp + 0x2c]
            //   7429                 | dec                 esp
            //   410fb700             | mov                 eax, edi
            //   6683f85c             | jb                  0xfcd
            //   7406                 | xorps               xmm0, xmm0

    condition:
        7 of them and filesize < 1286144
}