rule win_megacortex_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.megacortex."
        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.megacortex"
        malpedia_rule_date = "20230124"
        malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686"
        malpedia_version = "20230125"
        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 = { 8b4520 53 89858cfbffff 8b4524 56 8b7508 8985b4fbffff }
            // n = 7, score = 400
            //   8b4520               | mov                 eax, dword ptr [ebp + 0x20]
            //   53                   | push                ebx
            //   89858cfbffff         | mov                 dword ptr [ebp - 0x474], eax
            //   8b4524               | mov                 eax, dword ptr [ebp + 0x24]
            //   56                   | push                esi
            //   8b7508               | mov                 esi, dword ptr [ebp + 8]
            //   8985b4fbffff         | mov                 dword ptr [ebp - 0x44c], eax

        $sequence_1 = { 8d4b04 1bd2 2bc7 23d0 8d45e8 03d6 }
            // n = 6, score = 400
            //   8d4b04               | lea                 ecx, [ebx + 4]
            //   1bd2                 | sbb                 edx, edx
            //   2bc7                 | sub                 eax, edi
            //   23d0                 | and                 edx, eax
            //   8d45e8               | lea                 eax, [ebp - 0x18]
            //   03d6                 | add                 edx, esi

        $sequence_2 = { 83e0fe 8d75fc 03c8 8d45fc 2bc7 5f 8d51ff }
            // n = 7, score = 400
            //   83e0fe               | and                 eax, 0xfffffffe
            //   8d75fc               | lea                 esi, [ebp - 4]
            //   03c8                 | add                 ecx, eax
            //   8d45fc               | lea                 eax, [ebp - 4]
            //   2bc7                 | sub                 eax, edi
            //   5f                   | pop                 edi
            //   8d51ff               | lea                 edx, [ecx - 1]

        $sequence_3 = { 6bc758 51 51 2bf0 56 53 e8???????? }
            // n = 7, score = 400
            //   6bc758               | imul                eax, edi, 0x58
            //   51                   | push                ecx
            //   51                   | push                ecx
            //   2bf0                 | sub                 esi, eax
            //   56                   | push                esi
            //   53                   | push                ebx
            //   e8????????           |                     

        $sequence_4 = { e8???????? 83c404 eb02 33f6 897704 6a01 56 }
            // n = 7, score = 400
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   eb02                 | jmp                 4
            //   33f6                 | xor                 esi, esi
            //   897704               | mov                 dword ptr [edi + 4], esi
            //   6a01                 | push                1
            //   56                   | push                esi

        $sequence_5 = { 51 0f4385e09cffff 8d8d989cffff 50 6a00 e8???????? eb21 }
            // n = 7, score = 400
            //   51                   | push                ecx
            //   0f4385e09cffff       | cmovae              eax, dword ptr [ebp - 0x6320]
            //   8d8d989cffff         | lea                 ecx, [ebp - 0x6368]
            //   50                   | push                eax
            //   6a00                 | push                0
            //   e8????????           |                     
            //   eb21                 | jmp                 0x23

        $sequence_6 = { 33c0 8be5 5d c3 b8abaaaaaa f7e1 33c0 }
            // n = 7, score = 400
            //   33c0                 | xor                 eax, eax
            //   8be5                 | mov                 esp, ebp
            //   5d                   | pop                 ebp
            //   c3                   | ret                 
            //   b8abaaaaaa           | mov                 eax, 0xaaaaaaab
            //   f7e1                 | mul                 ecx
            //   33c0                 | xor                 eax, eax

        $sequence_7 = { 1bc9 23ca 8d55ec 8bd9 2bda 85c9 b901000000 }
            // n = 7, score = 400
            //   1bc9                 | sbb                 ecx, ecx
            //   23ca                 | and                 ecx, edx
            //   8d55ec               | lea                 edx, [ebp - 0x14]
            //   8bd9                 | mov                 ebx, ecx
            //   2bda                 | sub                 ebx, edx
            //   85c9                 | test                ecx, ecx
            //   b901000000           | mov                 ecx, 1

        $sequence_8 = { 8b4d08 8bd0 83c404 c702???????? 0f1001 0f114208 f30f7e4110 }
            // n = 7, score = 400
            //   8b4d08               | mov                 ecx, dword ptr [ebp + 8]
            //   8bd0                 | mov                 edx, eax
            //   83c404               | add                 esp, 4
            //   c702????????         |                     
            //   0f1001               | movups              xmm0, xmmword ptr [ecx]
            //   0f114208             | movups              xmmword ptr [edx + 8], xmm0
            //   f30f7e4110           | movq                xmm0, qword ptr [ecx + 0x10]

        $sequence_9 = { e8???????? ff75ec 8d4d20 e8???????? 8b36 3bf7 0f8578ffffff }
            // n = 7, score = 400
            //   e8????????           |                     
            //   ff75ec               | push                dword ptr [ebp - 0x14]
            //   8d4d20               | lea                 ecx, [ebp + 0x20]
            //   e8????????           |                     
            //   8b36                 | mov                 esi, dword ptr [esi]
            //   3bf7                 | cmp                 esi, edi
            //   0f8578ffffff         | jne                 0xffffff7e

    condition:
        7 of them and filesize < 1556480
}