rule win_atharvan_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.atharvan."
        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.atharvan"
        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 = { 660f1f440000 80f1ab 418808 4d8d4001 }
            // n = 4, score = 100
            //   660f1f440000         | dec                 eax
            //   80f1ab               | lea                 ecx, [0x15b91]
            //   418808               | dec                 eax
            //   4d8d4001             | mov                 eax, dword ptr [ebp - 0x28]

        $sequence_1 = { 488d4901 0fb601 84c0 75f1 488d542420 488bcb e8???????? }
            // n = 7, score = 100
            //   488d4901             | dec                 esp
            //   0fb601               | mov                 dword ptr [esp + 0x90], esi
            //   84c0                 | add                 ecx, 1
            //   75f1                 | dec                 eax
            //   488d542420           | mov                 eax, 0xffffffff
            //   488bcb               | test                eax, eax
            //   e8????????           |                     

        $sequence_2 = { 4833c4 48898550030000 488bf2 488bf9 33d2 488d8d40020000 41b804010000 }
            // n = 7, score = 100
            //   4833c4               | mov                 dword ptr [ebx + 0x224], 0x14
            //   48898550030000       | dec                 eax
            //   488bf2               | mov                 eax, ebx
            //   488bf9               | mov                 dword ptr [ebx + 0x22c], 0
            //   33d2                 | movups              xmmword ptr [ebx + 0x230], xmm0
            //   488d8d40020000       | movups              xmmword ptr [ebx + 0x240], xmm0
            //   41b804010000         | movups              xmmword ptr [ebx + 0x250], xmm0

        $sequence_3 = { 4b87bcfeb05c0200 33c0 488b5c2450 488b6c2458 488b742460 4883c420 }
            // n = 6, score = 100
            //   4b87bcfeb05c0200     | inc                 eax
            //   33c0                 | dec                 eax
            //   488b5c2450           | lea                 ecx, [ebp - 8]
            //   488b6c2458           | dec                 eax
            //   488b742460           | lea                 edx, [0x1c6b5]
            //   4883c420             | dec                 eax

        $sequence_4 = { eb42 85c9 782e 3b0d???????? 7326 4863c9 488d15cc0b0100 }
            // n = 7, score = 100
            //   eb42                 | add                 esp, 0x20
            //   85c9                 | je                  0x14c1
            //   782e                 | mov                 al, 1
            //   3b0d????????         |                     
            //   7326                 | dec                 eax
            //   4863c9               | add                 esp, 0x28
            //   488d15cc0b0100       | ret                 

        $sequence_5 = { ff15???????? 488b4d88 33d2 ff15???????? }
            // n = 4, score = 100
            //   ff15????????         |                     
            //   488b4d88             | dec                 eax
            //   33d2                 | lea                 edi, [0x132a0]
            //   ff15????????         |                     

        $sequence_6 = { 7418 660f1f840000000000 34ab 8801 488d4901 0fb601 }
            // n = 6, score = 100
            //   7418                 | sub                 al, 0
            //   660f1f840000000000     | add    cl, bh
            //   34ab                 | sub                 al, 0
            //   8801                 | add                 byte ptr [eax], dh
            //   488d4901             | sub                 dword ptr [eax], eax
            //   0fb601               | add                 byte ptr [ebp - 0x20ffffd5], bl

        $sequence_7 = { 48c1e602 0fb784b990a90100 488d9180a00100 488d8d24030000 }
            // n = 4, score = 100
            //   48c1e602             | dec                 esp
            //   0fb784b990a90100     | lea                 esi, [0x10512]
            //   488d9180a00100       | and                 eax, 0x3f
            //   488d8d24030000       | dec                 eax

        $sequence_8 = { 488b4530 488b8888000000 488d053a2f0100 483bc8 7405 e8???????? c70301000000 }
            // n = 7, score = 100
            //   488b4530             | mov                 byte ptr [eax], cl
            //   488b8888000000       | dec                 esp
            //   488d053a2f0100       | lea                 eax, [0xa0bf]
            //   483bc8               | dec                 eax
            //   7405                 | mov                 edx, ebx
            //   e8????????           |                     
            //   c70301000000         | mov                 ecx, edi

        $sequence_9 = { 488d4c2448 c7442449a1efc4dc c744244dc5c7c4ca c7442451cf8bfbca c7442455d9cac6ce }
            // n = 5, score = 100
            //   488d4c2448           | add                 byte ptr [eax], dh
            //   c7442449a1efc4dc     | sub                 dword ptr [eax], eax
            //   c744244dc5c7c4ca     | add                 byte ptr [ebp - 0x20ffffd5], bl
            //   c7442451cf8bfbca     | sub                 al, 0
            //   c7442455d9cac6ce     | sub                 al, 0

    condition:
        7 of them and filesize < 348160
}