rule win_ramsay_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-09-17"
        version = "1"
        description = "Detects win.ramsay."
        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.ramsay"
        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 = { 83f820 7502 eb07 33c0 }
            // n = 4, score = 600
            //   83f820               | cmp                 eax, 0x20
            //   7502                 | jne                 4
            //   eb07                 | jmp                 9
            //   33c0                 | xor                 eax, eax

        $sequence_1 = { ff15???????? 85c0 7502 eb02 ebb1 }
            // n = 5, score = 600
            //   ff15????????         |                     
            //   85c0                 | test                eax, eax
            //   7502                 | jne                 4
            //   eb02                 | jmp                 4
            //   ebb1                 | jmp                 0xffffffb3

        $sequence_2 = { 7514 ff15???????? 83f820 7502 }
            // n = 4, score = 600
            //   7514                 | jne                 0x16
            //   ff15????????         |                     
            //   83f820               | cmp                 eax, 0x20
            //   7502                 | jne                 4

        $sequence_3 = { 837df808 731e 8b45f8 3b450c }
            // n = 4, score = 500
            //   837df808             | dec                 eax
            //   731e                 | mov                 dword ptr [esp + 0x1838], 0
            //   8b45f8               | dec                 eax
            //   3b450c               | mov                 dword ptr [esp + 0x1840], 0

        $sequence_4 = { 8b55fc 52 e8???????? 83c404 33c0 eb0d 8b45f8 }
            // n = 7, score = 500
            //   8b55fc               | mov                 edx, dword ptr [ebp - 4]
            //   52                   | push                edx
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   33c0                 | xor                 eax, eax
            //   eb0d                 | jmp                 0xf
            //   8b45f8               | mov                 eax, dword ptr [ebp - 8]

        $sequence_5 = { 8bec 83ec08 c745f800000000 6a00 6880000000 6a02 6a00 }
            // n = 7, score = 500
            //   8bec                 | mov                 ebp, esp
            //   83ec08               | sub                 esp, 8
            //   c745f800000000       | mov                 dword ptr [ebp - 8], 0
            //   6a00                 | push                0
            //   6880000000           | push                0x80
            //   6a02                 | push                2
            //   6a00                 | push                0

        $sequence_6 = { 8b5508 8b4508 8a481e 884a08 }
            // n = 4, score = 500
            //   8b5508               | xor                 eax, eax
            //   8b4508               | mov                 word ptr [esp + 0x1820], ax
            //   8a481e               | dec                 eax
            //   884a08               | mov                 dword ptr [esp + 0x1830], 0

        $sequence_7 = { 8b95c4fdffff 52 ff15???????? 33c0 }
            // n = 4, score = 500
            //   8b95c4fdffff         | mov                 edx, dword ptr [ebp - 0x23c]
            //   52                   | push                edx
            //   ff15????????         |                     
            //   33c0                 | xor                 eax, eax

        $sequence_8 = { 8b55fc 52 e8???????? 8945ec 837dec00 7561 8b45fc }
            // n = 7, score = 500
            //   8b55fc               | mov                 edx, dword ptr [ebp - 4]
            //   52                   | push                edx
            //   e8????????           |                     
            //   8945ec               | mov                 dword ptr [ebp - 0x14], eax
            //   837dec00             | cmp                 dword ptr [ebp - 0x14], 0
            //   7561                 | jne                 0x63
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]

        $sequence_9 = { 8b4508 8a480b 884a1e 8b5508 8b4508 8a481c 884a0b }
            // n = 7, score = 500
            //   8b4508               | dec                 eax
            //   8a480b               | lea                 ecx, [esp + 0xe8]
            //   884a1e               | dec                 eax
            //   8b5508               | lea                 ecx, [esp + 0xe8]
            //   8b4508               | dec                 eax
            //   8a481c               | lea                 ecx, [esp + 0xe8]
            //   884a0b               | dec                 eax

        $sequence_10 = { 8b8dc4fdffff 51 e8???????? 85c0 7511 8b95c4fdffff 52 }
            // n = 7, score = 500
            //   8b8dc4fdffff         | mov                 ecx, dword ptr [ebp - 0x23c]
            //   51                   | push                ecx
            //   e8????????           |                     
            //   85c0                 | test                eax, eax
            //   7511                 | jne                 0x13
            //   8b95c4fdffff         | mov                 edx, dword ptr [ebp - 0x23c]
            //   52                   | push                edx

        $sequence_11 = { ff15???????? 33c0 e9???????? e8???????? 85c0 }
            // n = 5, score = 400
            //   ff15????????         |                     
            //   33c0                 | xor                 eax, eax
            //   e9????????           |                     
            //   e8????????           |                     
            //   85c0                 | test                eax, eax

        $sequence_12 = { 488d8c24e0090000 ff15???????? 85c0 7505 e9???????? 488b8c2408050000 }
            // n = 6, score = 200
            //   488d8c24e0090000     | dec                 eax
            //   ff15????????         |                     
            //   85c0                 | lea                 ecx, [esp + 0x9e0]
            //   7505                 | test                eax, eax
            //   e9????????           |                     
            //   488b8c2408050000     | jne                 9

        $sequence_13 = { 488d8c24e8000000 ff15???????? 488d8c24e8000000 ff15???????? }
            // n = 4, score = 200
            //   488d8c24e8000000     | dec                 eax
            //   ff15????????         |                     
            //   488d8c24e8000000     | lea                 ecx, [esp + 0x17e0]
            //   ff15????????         |                     

        $sequence_14 = { 488d8c24e0090000 ff15???????? 488d8c24e0090000 ff15???????? 85c0 7519 33d2 }
            // n = 7, score = 200
            //   488d8c24e0090000     | dec                 eax
            //   ff15????????         |                     
            //   488d8c24e0090000     | lea                 ecx, [esp + 0x9e0]
            //   ff15????????         |                     
            //   85c0                 | dec                 eax
            //   7519                 | lea                 ecx, [esp + 0x9e0]
            //   33d2                 | test                eax, eax

        $sequence_15 = { 488d8c24e0170000 ff15???????? 33c0 6689842420180000 }
            // n = 4, score = 200
            //   488d8c24e0170000     | dec                 eax
            //   ff15????????         |                     
            //   33c0                 | lea                 ecx, [esp + 0x9e0]
            //   6689842420180000     | test                eax, eax

    condition:
        7 of them and filesize < 2031616
}