rule win_snojan_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.snojan."
        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.snojan"
        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 = { 6689442422 8d442420 c744240810000000 893c24 89442404 ff15???????? 83ec0c }
            // n = 7, score = 200
            //   6689442422           | mov                 word ptr [esp + 0x22], ax
            //   8d442420             | lea                 eax, [esp + 0x20]
            //   c744240810000000     | mov                 dword ptr [esp + 8], 0x10
            //   893c24               | mov                 dword ptr [esp], edi
            //   89442404             | mov                 dword ptr [esp + 4], eax
            //   ff15????????         |                     
            //   83ec0c               | sub                 esp, 0xc

        $sequence_1 = { 8b13 83c308 03960000986d 8d860000986d 8955cc }
            // n = 5, score = 200
            //   8b13                 | mov                 edx, dword ptr [ebx]
            //   83c308               | add                 ebx, 8
            //   03960000986d         | add                 edx, dword ptr [esi + 0x6d980000]
            //   8d860000986d         | lea                 eax, [esi + 0x6d980000]
            //   8955cc               | mov                 dword ptr [ebp - 0x34], edx

        $sequence_2 = { 89442404 ff15???????? 83ec0c 83f8ff 0f8452010000 c7442404???????? c70424???????? }
            // n = 7, score = 200
            //   89442404             | mov                 dword ptr [esp + 4], eax
            //   ff15????????         |                     
            //   83ec0c               | sub                 esp, 0xc
            //   83f8ff               | cmp                 eax, -1
            //   0f8452010000         | je                  0x158
            //   c7442404????????     |                     
            //   c70424????????       |                     

        $sequence_3 = { 74e7 a1???????? 8d900000986d 0fb7801400986d 0fb76a06 }
            // n = 5, score = 200
            //   74e7                 | je                  0xffffffe9
            //   a1????????           |                     
            //   8d900000986d         | lea                 edx, [eax + 0x6d980000]
            //   0fb7801400986d       | movzx               eax, word ptr [eax + 0x6d980014]
            //   0fb76a06             | movzx               ebp, word ptr [edx + 6]

        $sequence_4 = { ff15???????? 83ec0c 83f8ff 0f8452010000 c7442404???????? c70424???????? }
            // n = 6, score = 200
            //   ff15????????         |                     
            //   83ec0c               | sub                 esp, 0xc
            //   83f8ff               | cmp                 eax, -1
            //   0f8452010000         | je                  0x158
            //   c7442404????????     |                     
            //   c70424????????       |                     

        $sequence_5 = { c744240810000000 893c24 89442404 ff15???????? 83ec0c 83f8ff }
            // n = 6, score = 200
            //   c744240810000000     | mov                 dword ptr [esp + 8], 0x10
            //   893c24               | mov                 dword ptr [esp], edi
            //   89442404             | mov                 dword ptr [esp + 4], eax
            //   ff15????????         |                     
            //   83ec0c               | sub                 esp, 0xc
            //   83f8ff               | cmp                 eax, -1

        $sequence_6 = { ff15???????? 81c43c900100 b801000000 5b 5e }
            // n = 5, score = 200
            //   ff15????????         |                     
            //   81c43c900100         | add                 esp, 0x1903c
            //   b801000000           | mov                 eax, 1
            //   5b                   | pop                 ebx
            //   5e                   | pop                 esi

        $sequence_7 = { 894dc0 89c7 81cf0000ffff 6683b90000986d00 0f48c7 8b7dc4 2d???????? }
            // n = 7, score = 200
            //   894dc0               | mov                 dword ptr [ebp - 0x40], ecx
            //   89c7                 | mov                 edi, eax
            //   81cf0000ffff         | or                  edi, 0xffff0000
            //   6683b90000986d00     | cmp                 word ptr [ecx + 0x6d980000], 0
            //   0f48c7               | cmovs               eax, edi
            //   8b7dc4               | mov                 edi, dword ptr [ebp - 0x3c]
            //   2d????????           |                     

        $sequence_8 = { 83ec04 6689442422 8d442420 c744240810000000 893c24 89442404 ff15???????? }
            // n = 7, score = 200
            //   83ec04               | sub                 esp, 4
            //   6689442422           | mov                 word ptr [esp + 0x22], ax
            //   8d442420             | lea                 eax, [esp + 0x20]
            //   c744240810000000     | mov                 dword ptr [esp + 8], 0x10
            //   893c24               | mov                 dword ptr [esp], edi
            //   89442404             | mov                 dword ptr [esp + 4], eax
            //   ff15????????         |                     

        $sequence_9 = { 31db eb02 89c3 8d4301 8b14859026986d 85d2 }
            // n = 6, score = 200
            //   31db                 | xor                 ebx, ebx
            //   eb02                 | jmp                 4
            //   89c3                 | mov                 ebx, eax
            //   8d4301               | lea                 eax, [ebx + 1]
            //   8b14859026986d       | mov                 edx, dword ptr [eax*4 + 0x6d982690]
            //   85d2                 | test                edx, edx

    condition:
        7 of them and filesize < 90112
}