rule win_megumin_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-08-05"
        version = "1"
        description = "Detects win.megumin."
        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.megumin"
        malpedia_rule_date = "20220805"
        malpedia_hash = "6ec06c64bcfdbeda64eff021c766b4ce34542b71"
        malpedia_version = "20220808"
        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 = { e8???????? c645fc06 50 b9???????? e8???????? 8d8db8fdffff }
            // n = 6, score = 200
            //   e8????????           |                     
            //   c645fc06             | mov                 byte ptr [ebp - 4], 6
            //   50                   | push                eax
            //   b9????????           |                     
            //   e8????????           |                     
            //   8d8db8fdffff         | lea                 ecx, [ebp - 0x248]

        $sequence_1 = { 8b531c 8bc2 8b4b18 2bc1 6a03 68???????? 83f803 }
            // n = 7, score = 200
            //   8b531c               | mov                 edx, dword ptr [ebx + 0x1c]
            //   8bc2                 | mov                 eax, edx
            //   8b4b18               | mov                 ecx, dword ptr [ebx + 0x18]
            //   2bc1                 | sub                 eax, ecx
            //   6a03                 | push                3
            //   68????????           |                     
            //   83f803               | cmp                 eax, 3

        $sequence_2 = { a804 7411 83e0fb 8d4d94 8945ec e8???????? }
            // n = 6, score = 200
            //   a804                 | test                al, 4
            //   7411                 | je                  0x13
            //   83e0fb               | and                 eax, 0xfffffffb
            //   8d4d94               | lea                 ecx, [ebp - 0x6c]
            //   8945ec               | mov                 dword ptr [ebp - 0x14], eax
            //   e8????????           |                     

        $sequence_3 = { 8b45e0 89460c 8b4dc0 8d45e4 3bc8 740e ff75c0 }
            // n = 7, score = 200
            //   8b45e0               | mov                 eax, dword ptr [ebp - 0x20]
            //   89460c               | mov                 dword ptr [esi + 0xc], eax
            //   8b4dc0               | mov                 ecx, dword ptr [ebp - 0x40]
            //   8d45e4               | lea                 eax, [ebp - 0x1c]
            //   3bc8                 | cmp                 ecx, eax
            //   740e                 | je                  0x10
            //   ff75c0               | push                dword ptr [ebp - 0x40]

        $sequence_4 = { 8d8d4cfdffff e8???????? 83c404 8d8db4fdffff c645fc0e 51 8bd0 }
            // n = 7, score = 200
            //   8d8d4cfdffff         | lea                 ecx, [ebp - 0x2b4]
            //   e8????????           |                     
            //   83c404               | add                 esp, 4
            //   8d8db4fdffff         | lea                 ecx, [ebp - 0x24c]
            //   c645fc0e             | mov                 byte ptr [ebp - 4], 0xe
            //   51                   | push                ecx
            //   8bd0                 | mov                 edx, eax

        $sequence_5 = { 50 52 e8???????? eba8 f7466020200000 7407 8b464c }
            // n = 7, score = 200
            //   50                   | push                eax
            //   52                   | push                edx
            //   e8????????           |                     
            //   eba8                 | jmp                 0xffffffaa
            //   f7466020200000       | test                dword ptr [esi + 0x60], 0x2020
            //   7407                 | je                  9
            //   8b464c               | mov                 eax, dword ptr [esi + 0x4c]

        $sequence_6 = { 8965b8 68???????? e8???????? 83ec18 c645fc59 8bf4 }
            // n = 6, score = 200
            //   8965b8               | mov                 dword ptr [ebp - 0x48], esp
            //   68????????           |                     
            //   e8????????           |                     
            //   83ec18               | sub                 esp, 0x18
            //   c645fc59             | mov                 byte ptr [ebp - 4], 0x59
            //   8bf4                 | mov                 esi, esp

        $sequence_7 = { 83f810 0f434db8 8b36 8b5614 8bc2 8b5e10 2bc3 }
            // n = 7, score = 200
            //   83f810               | cmp                 eax, 0x10
            //   0f434db8             | cmovae              ecx, dword ptr [ebp - 0x48]
            //   8b36                 | mov                 esi, dword ptr [esi]
            //   8b5614               | mov                 edx, dword ptr [esi + 0x14]
            //   8bc2                 | mov                 eax, edx
            //   8b5e10               | mov                 ebx, dword ptr [esi + 0x10]
            //   2bc3                 | sub                 eax, ebx

        $sequence_8 = { 6848010000 8d8558feffff 6a00 50 e8???????? 83c40c }
            // n = 6, score = 200
            //   6848010000           | push                0x148
            //   8d8558feffff         | lea                 eax, [ebp - 0x1a8]
            //   6a00                 | push                0
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc

        $sequence_9 = { 8bca 83e103 f3a4 8d8dacfdffff e8???????? 8d85d0feffff 50 }
            // n = 7, score = 200
            //   8bca                 | mov                 ecx, edx
            //   83e103               | and                 ecx, 3
            //   f3a4                 | rep movsb           byte ptr es:[edi], byte ptr [esi]
            //   8d8dacfdffff         | lea                 ecx, [ebp - 0x254]
            //   e8????????           |                     
            //   8d85d0feffff         | lea                 eax, [ebp - 0x130]
            //   50                   | push                eax

    condition:
        7 of them and filesize < 1007616
}

rule win_megumin_w0 {
    meta:
        description = "Detecting Megumin v2"
        author = "Fumik0_"
        date = "2019-05-02"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.megumin"
        malpedia_version = "20190503"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
        
    strings:
        $s1 = "Megumin/2.0" wide ascii
        $s2 = "/cpu" wide ascii
        $s3 = "/task?hwid=" wide ascii
        $s4 = "/gate?hwid=" wide ascii
        $s5 = "/suicide" wide ascii

    condition:
        all of them
}