rule win_atomsilo_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects win.atomsilo."
        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.atomsilo"
        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 = { e8???????? 90 84db 0f84e3000000 ba01000000 488d4de0 }
            // n = 6, score = 100
            //   e8????????           |                     
            //   90                   | mov                 byte ptr [ebp - 0x68], 0x28
            //   84db                 | mov                 byte ptr [ebp - 0x67], 0x22
            //   0f84e3000000         | mov                 byte ptr [ebp - 0x66], al
            //   ba01000000           | movzx               eax, byte ptr [ebp - 0x6c]
            //   488d4de0             | nop                 

        $sequence_1 = { 33ed 896808 40382d???????? 750c e8???????? c605????????01 488d05824c0600 }
            // n = 7, score = 100
            //   33ed                 | or                  edx, 0x80070000
            //   896808               | test                eax, eax
            //   40382d????????       |                     
            //   750c                 | cmovle              edx, eax
            //   e8????????           |                     
            //   c605????????01       |                     
            //   488d05824c0600       | dec                 eax

        $sequence_2 = { 4889442458 33c9 894c2460 48c70001000000 48894808 c744243004000000 488b4e18 }
            // n = 7, score = 100
            //   4889442458           | mov                 dword ptr [eax], ebp
            //   33c9                 | dec                 esp
            //   894c2460             | mov                 ecx, edi
            //   48c70001000000       | dec                 esp
            //   48894808             | mov                 eax, esi
            //   c744243004000000     | dec                 eax
            //   488b4e18             | lea                 edx, [esp + 0x30]

        $sequence_3 = { 498bc3 49f7e9 4c8bfa 49c1ff05 498bc7 48c1e83f 4c03f8 }
            // n = 7, score = 100
            //   498bc3               | dec                 eax
            //   49f7e9               | mov                 ebx, eax
            //   4c8bfa               | dec                 ecx
            //   49c1ff05             | mov                 edi, dword ptr [esi]
            //   498bc7               | dec                 eax
            //   48c1e83f             | lea                 edx, [esp + 0x28]
            //   4c03f8               | dec                 ecx

        $sequence_4 = { 90 488bd0 488d4e60 e8???????? 90 488b4d60 48394d58 }
            // n = 7, score = 100
            //   90                   | mov                 dword ptr [ebp + 0xf0], eax
            //   488bd0               | nop                 
            //   488d4e60             | inc                 ecx
            //   e8????????           |                     
            //   90                   | mov                 eax, 1
            //   488b4d60             | dec                 eax
            //   48394d58             | mov                 edx, eax

        $sequence_5 = { 8844245a 8b442450 0407 83f04f 8844245b 8b442450 }
            // n = 6, score = 100
            //   8844245a             | dec                 eax
            //   8b442450             | lea                 ecx, [esp + 0x48]
            //   0407                 | dec                 eax
            //   83f04f               | lea                 edx, [0x6cc89]
            //   8844245b             | or                  edx, 0x80070000
            //   8b442450             | test                eax, eax

        $sequence_6 = { 7235 488b8990000000 48ffc2 4881fa00100000 721c 4883c227 488b79f8 }
            // n = 7, score = 100
            //   7235                 | shr                 ecx, 1
            //   488b8990000000       | movdqa              xmmword ptr [esp + 0x20], xmm0
            //   48ffc2               | dec                 esp
            //   4881fa00100000       | lea                 eax, [esp + 0x30]
            //   721c                 | dec                 eax
            //   4883c227             | lea                 edx, [0x614df]
            //   488b79f8             | dec                 eax

        $sequence_7 = { e8???????? 90 4584ff 7454 488bce e8???????? 8bf8 }
            // n = 7, score = 100
            //   e8????????           |                     
            //   90                   | add                 ecx, edi
            //   4584ff               | call                dword ptr [ebx + 0x20]
            //   7454                 | dec                 eax
            //   488bce               | lea                 eax, [0x6003d]
            //   e8????????           |                     
            //   8bf8                 | dec                 eax

        $sequence_8 = { ba01000000 e9???????? 837dd801 0f84c8000000 833d????????01 0f8485010000 488b45c8 }
            // n = 7, score = 100
            //   ba01000000           | mov                 esp, dword ptr [esp + 0x50]
            //   e9????????           |                     
            //   837dd801             | dec                 ebp
            //   0f84c8000000         | mov                 eax, esp
            //   833d????????01       |                     
            //   0f8485010000         | dec                 eax
            //   488b45c8             | lea                 edx, [ebp + 0xe0]

        $sequence_9 = { 4c2b5c2438 498d7d01 4c8b9424d0000000 488d3cfe 4c8b642430 4c2beb 4c2bde }
            // n = 7, score = 100
            //   4c2b5c2438           | lea                 eax, [ebx + edi]
            //   498d7d01             | dec                 ecx
            //   4c8b9424d0000000     | cmp                 eax, esi
            //   488d3cfe             | jbe                 0x376
            //   4c8b642430           | dec                 ebx
            //   4c2beb               | lea                 eax, [esi + eax]
            //   4c2bde               | dec                 esp

    condition:
        7 of them and filesize < 1785856
}