rule win_nestegg_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.nestegg."
        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.nestegg"
        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 = { 51 52 895c2428 895c2424 aa ff15???????? b909000000 }
            // n = 7, score = 200
            //   51                   | push                ecx
            //   52                   | push                edx
            //   895c2428             | mov                 dword ptr [esp + 0x28], ebx
            //   895c2424             | mov                 dword ptr [esp + 0x24], ebx
            //   aa                   | stosb               byte ptr es:[edi], al
            //   ff15????????         |                     
            //   b909000000           | mov                 ecx, 9

        $sequence_1 = { e8???????? 6840040000 c68424c000000003 e8???????? 83c404 }
            // n = 5, score = 200
            //   e8????????           |                     
            //   6840040000           | push                0x440
            //   c68424c000000003     | mov                 byte ptr [esp + 0xc0], 3
            //   e8????????           |                     
            //   83c404               | add                 esp, 4

        $sequence_2 = { 8d942498010000 52 ff15???????? 83c40c 8d442438 8d4c2448 }
            // n = 6, score = 200
            //   8d942498010000       | lea                 edx, [esp + 0x198]
            //   52                   | push                edx
            //   ff15????????         |                     
            //   83c40c               | add                 esp, 0xc
            //   8d442438             | lea                 eax, [esp + 0x38]
            //   8d4c2448             | lea                 ecx, [esp + 0x48]

        $sequence_3 = { ff15???????? 83c410 8d442430 8d8c247c010000 53 50 51 }
            // n = 7, score = 200
            //   ff15????????         |                     
            //   83c410               | add                 esp, 0x10
            //   8d442430             | lea                 eax, [esp + 0x30]
            //   8d8c247c010000       | lea                 ecx, [esp + 0x17c]
            //   53                   | push                ebx
            //   50                   | push                eax
            //   51                   | push                ecx

        $sequence_4 = { 66894104 a1???????? 85c0 7464 8d542408 8d4c240c }
            // n = 6, score = 200
            //   66894104             | mov                 word ptr [ecx + 4], ax
            //   a1????????           |                     
            //   85c0                 | test                eax, eax
            //   7464                 | je                  0x66
            //   8d542408             | lea                 edx, [esp + 8]
            //   8d4c240c             | lea                 ecx, [esp + 0xc]

        $sequence_5 = { 8d442410 8d4c2428 50 57 57 51 53 }
            // n = 7, score = 200
            //   8d442410             | lea                 eax, [esp + 0x10]
            //   8d4c2428             | lea                 ecx, [esp + 0x28]
            //   50                   | push                eax
            //   57                   | push                edi
            //   57                   | push                edi
            //   51                   | push                ecx
            //   53                   | push                ebx

        $sequence_6 = { 50 e8???????? 83c40c 8bd8 8b442410 }
            // n = 5, score = 200
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   8bd8                 | mov                 ebx, eax
            //   8b442410             | mov                 eax, dword ptr [esp + 0x10]

        $sequence_7 = { 896c2434 ffd0 85c0 747e 8b442414 33ff 3bc5 }
            // n = 7, score = 200
            //   896c2434             | mov                 dword ptr [esp + 0x34], ebp
            //   ffd0                 | call                eax
            //   85c0                 | test                eax, eax
            //   747e                 | je                  0x80
            //   8b442414             | mov                 eax, dword ptr [esp + 0x14]
            //   33ff                 | xor                 edi, edi
            //   3bc5                 | cmp                 eax, ebp

        $sequence_8 = { 8d442410 6aff 6a01 50 6a02 ff15???????? }
            // n = 6, score = 200
            //   8d442410             | lea                 eax, [esp + 0x10]
            //   6aff                 | push                -1
            //   6a01                 | push                1
            //   50                   | push                eax
            //   6a02                 | push                2
            //   ff15????????         |                     

        $sequence_9 = { 8d4c2444 50 51 8b0d???????? e8???????? e9???????? 83f80d }
            // n = 7, score = 200
            //   8d4c2444             | lea                 ecx, [esp + 0x44]
            //   50                   | push                eax
            //   51                   | push                ecx
            //   8b0d????????         |                     
            //   e8????????           |                     
            //   e9????????           |                     
            //   83f80d               | cmp                 eax, 0xd

    condition:
        7 of them and filesize < 221184
}