rule win_chaperone_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.chaperone."
        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.chaperone"
        malpedia_rule_date = "20230705"
        malpedia_hash = "42d0574f4405bd7d2b154d321d345acb18834a41"
        malpedia_version = "20230715"
        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 = { 488b8424a0050000 488914c8 488b8424b8050000 8b00 83e801 4898 488d542430 }
            // n = 7, score = 100
            //   488b8424a0050000     | dec                 eax
            //   488914c8             | mov                 eax, dword ptr [esp + 0x40]
            //   488b8424b8050000     | dec                 eax
            //   8b00                 | mov                 dword ptr [eax + 0x240], 0
            //   83e801               | dec                 eax
            //   4898                 | mov                 eax, dword ptr [esp + 0x40]
            //   488d542430           | mov                 dword ptr [eax + 8], 0xffffffff

        $sequence_1 = { 488d542440 488b8c2498070000 e8???????? 488d542440 488d8c24a0020000 ff15???????? 66ba5c00 }
            // n = 7, score = 100
            //   488d542440           | mov                 edx, dword ptr [esp + 0xb0]
            //   488b8c2498070000     | dec                 eax
            //   e8????????           |                     
            //   488d542440           | mov                 eax, dword ptr [esp + 0xa0]
            //   488d8c24a0020000     | mov                 ecx, dword ptr [eax + ecx]
            //   ff15????????         |                     
            //   66ba5c00             | jne                 0xa38

        $sequence_2 = { e8???????? 85c0 742d 488d0567a70100 4883c310 }
            // n = 5, score = 100
            //   e8????????           |                     
            //   85c0                 | dec                 eax
            //   742d                 | mov                 edx, eax
            //   488d0567a70100       | dec                 eax
            //   4883c310             | mov                 eax, dword ptr [esp + 0x5b8]

        $sequence_3 = { ff15???????? 85c0 750a c744243001000000 eb02 eb9e 837c243000 }
            // n = 7, score = 100
            //   ff15????????         |                     
            //   85c0                 | inc                 ebp
            //   750a                 | xor                 ecx, ecx
            //   c744243001000000     | inc                 ecx
            //   eb02                 | mov                 eax, 1
            //   eb9e                 | mov                 edx, 0x80000000
            //   837c243000           | dec                 eax

        $sequence_4 = { e8???????? 488d7c2428 488d35eb9a0000 b91e000000 f3a4 }
            // n = 5, score = 100
            //   e8????????           |                     
            //   488d7c2428           | mov                 ecx, dword ptr [esp + ecx*8 + 0x240]
            //   488d35eb9a0000       | dec                 eax
            //   b91e000000           | lea                 edx, [esp + 0x30]
            //   f3a4                 | dec                 eax

        $sequence_5 = { b92e000000 f3a4 488dbc2488020000 488d35f8c40100 b926000000 f3a4 }
            // n = 6, score = 100
            //   b92e000000           | lea                 ecx, [0x1e610]
            //   f3a4                 | inc                 ebp
            //   488dbc2488020000     | xor                 eax, eax
            //   488d35f8c40100       | xor                 edx, edx
            //   b926000000           | xor                 ecx, ecx
            //   f3a4                 | dec                 eax

        $sequence_6 = { c6442457d0 c644245820 c644245902 c644245a15 }
            // n = 4, score = 100
            //   c6442457d0           | dec                 eax
            //   c644245820           | lea                 ecx, [esp + 0x2a0]
            //   c644245902           | mov                 dword ptr [esp + 0x74c], 0
            //   c644245a15           | dec                 eax

        $sequence_7 = { e8???????? c744242000000000 eb0b 8b442420 83c001 89442420 }
            // n = 6, score = 100
            //   e8????????           |                     
            //   c744242000000000     | lea                 eax, [0x17b9c]
            //   eb0b                 | dec                 eax
            //   8b442420             | sub                 esp, 0x20
            //   83c001               | dec                 eax
            //   89442420             | mov                 ebx, ecx

        $sequence_8 = { 488b8c24a0010000 ff15???????? 488905???????? 488d942480020000 488b8c24a0010000 ff15???????? 488905???????? }
            // n = 7, score = 100
            //   488b8c24a0010000     | dec                 esp
            //   ff15????????         |                     
            //   488905????????       |                     
            //   488d942480020000     | mov                 eax, dword ptr [esp + 0xe0]
            //   488b8c24a0010000     | dec                 esp
            //   ff15????????         |                     
            //   488905????????       |                     

        $sequence_9 = { 83bc247002000000 7419 488b542430 4881c238020000 488b4c2420 ff15???????? }
            // n = 6, score = 100
            //   83bc247002000000     | je                  0x116
            //   7419                 | dec                 eax
            //   488b542430           | lea                 ecx, [esp + 0x68]
            //   4881c238020000       | cmp                 eax, dword ptr [esp + 0x2d8]
            //   488b4c2420           | jb                  0x106
            //   ff15????????         |                     

    condition:
        7 of them and filesize < 373760
}