rule win_makop_ransomware_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2021-10-07"
        version = "1"
        description = "Detects win.makop_ransomware."
        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.makop_ransomware"
        malpedia_rule_date = "20211007"
        malpedia_hash = "e5b790e0f888f252d49063a1251ca60ec2832535"
        malpedia_version = "20211008"
        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 = { 75f7 2bc7 83e801 39442404 720a b001 }
            // n = 6, score = 100
            //   75f7                 | jne                 0xfffffff9
            //   2bc7                 | sub                 eax, edi
            //   83e801               | sub                 eax, 1
            //   39442404             | cmp                 dword ptr [esp + 4], eax
            //   720a                 | jb                  0xc
            //   b001                 | mov                 al, 1

        $sequence_1 = { 50 ff15???????? e8???????? 8b4c2404 51 }
            // n = 5, score = 100
            //   50                   | push                eax
            //   ff15????????         |                     
            //   e8????????           |                     
            //   8b4c2404             | mov                 ecx, dword ptr [esp + 4]
            //   51                   | push                ecx

        $sequence_2 = { 8bf0 56 ff15???????? 8b542418 }
            // n = 4, score = 100
            //   8bf0                 | mov                 esi, eax
            //   56                   | push                esi
            //   ff15????????         |                     
            //   8b542418             | mov                 edx, dword ptr [esp + 0x18]

        $sequence_3 = { 6685c9 7415 0fb74e02 0fb74202 83c602 }
            // n = 5, score = 100
            //   6685c9               | test                cx, cx
            //   7415                 | je                  0x17
            //   0fb74e02             | movzx               ecx, word ptr [esi + 2]
            //   0fb74202             | movzx               eax, word ptr [edx + 2]
            //   83c602               | add                 esi, 2

        $sequence_4 = { ff15???????? 8b44241c 8b35???????? 6a00 8d542418 }
            // n = 5, score = 100
            //   ff15????????         |                     
            //   8b44241c             | mov                 eax, dword ptr [esp + 0x1c]
            //   8b35????????         |                     
            //   6a00                 | push                0
            //   8d542418             | lea                 edx, dword ptr [esp + 0x18]

        $sequence_5 = { eb2f b8???????? 668b08 83c002 6685c9 75f5 2d???????? }
            // n = 7, score = 100
            //   eb2f                 | jmp                 0x31
            //   b8????????           |                     
            //   668b08               | mov                 cx, word ptr [eax]
            //   83c002               | add                 eax, 2
            //   6685c9               | test                cx, cx
            //   75f5                 | jne                 0xfffffff7
            //   2d????????           |                     

        $sequence_6 = { c3 668b0d???????? 83ec10 6685c9 56 b8???????? 7415 }
            // n = 7, score = 100
            //   c3                   | ret                 
            //   668b0d????????       |                     
            //   83ec10               | sub                 esp, 0x10
            //   6685c9               | test                cx, cx
            //   56                   | push                esi
            //   b8????????           |                     
            //   7415                 | je                  0x17

        $sequence_7 = { 85c0 750b 8906 32c0 5e 83c408 c20400 }
            // n = 7, score = 100
            //   85c0                 | test                eax, eax
            //   750b                 | jne                 0xd
            //   8906                 | mov                 dword ptr [esi], eax
            //   32c0                 | xor                 al, al
            //   5e                   | pop                 esi
            //   83c408               | add                 esp, 8
            //   c20400               | ret                 4

        $sequence_8 = { 8b542418 8bcd e8???????? 85c0 0f84d5010000 8b4c2418 51 }
            // n = 7, score = 100
            //   8b542418             | mov                 edx, dword ptr [esp + 0x18]
            //   8bcd                 | mov                 ecx, ebp
            //   e8????????           |                     
            //   85c0                 | test                eax, eax
            //   0f84d5010000         | je                  0x1db
            //   8b4c2418             | mov                 ecx, dword ptr [esp + 0x18]
            //   51                   | push                ecx

        $sequence_9 = { 894a08 8b4010 83f808 7308 6aff }
            // n = 5, score = 100
            //   894a08               | mov                 dword ptr [edx + 8], ecx
            //   8b4010               | mov                 eax, dword ptr [eax + 0x10]
            //   83f808               | cmp                 eax, 8
            //   7308                 | jae                 0xa
            //   6aff                 | push                -1

    condition:
        7 of them and filesize < 107520
}

rule win_makop_ransomware_w0 {
    meta:
        description = "Detects MAKOP ransomware payload"
        author = "@VK_Intel"
        reference = "https://twitter.com/VK_Intel/status/1242177227682390017"
        tlp = "white"
        date = "2020-03-23"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.makop_ransomware"
        malpedia_version = "20200325"
        malpedia_sharing = "TLP:WHITE"
        malpedia_license = ""

    strings:
        $str1 = "-%08X"
        $str2 = "MPR.dll"
        $str3 = "\\*.*" wide

        $dec1 = { 8b ?? ?? 6a 08 8d ?? ?? ?? 52 8d ?? ?? ?? 50 e8 ?? ?? ?? ?? 66 ?? ?? ?? ?? 66 ?? ?? ?? ?? 83 c4 0c 66 3b c1 76 ?? 0f b7 c9 0f b7 f8 2b f9 74 ?? 57 6a 00 ff ?? ?? ?? ?? ?? 50 ff ?? ?? ?? ?? ?? 8b d8 85 db 74 ?? 0f ?? ?? ?? ?? 03 ?? ?? 57 52 53 e8 ?? ?? ?? ?? 83 c4 0c 8d ?? ?? 55 ff ?? ?? ?? ?? ?? e8 ?? ?? ?? ?? 84 c0 74 ?? 8b ?? ?? ?? 50 53 6a 00 6a 00 89 ?? 8b ?? ?? 6a 00 50 ff ?? ?? ?? ?? ?? 85 c0 75 ?? ff ?? ?? ?? ?? ?? 50 e8 ?? ?? ?? ?? 83 c4 04 33 c0 5f 5e 5d 5b 83 c4 0c c2 08 00}
        $start = {55 8b ec 83 e4 f8 a1 ?? ?? ?? ?? 81 ec 64 02 00 00 85 c0 53 56 57 74 ?? 6a 00 50 ff ?? ?? ?? ?? ?? 85 c0 0f ?? ?? ?? ?? ?? 8b ?? ?? 0f ?? ?? ?? 8b ?? ?? 51 e8 ?? ?? ?? ?? 83 c4 04 84 c0 0f ?? ?? ?? ?? ?? 8b ?? ?? 8d ?? ?? 8d ?? ?? 85 c0 0f ?? ?? ?? ?? ?? 50 6a 00 ff ?? ?? ?? ?? ?? 50 ff ?? ?? ?? ?? ?? 8b f0 85 f6 0f ?? ?? ?? ?? ?? 8b ?? ?? 80 ?? ?? ?? 75 ?? 81 fb fa 00 00 00 72 ?? 8b ?? ?? ?? ?? ?? 8b de e8 ?? ?? ?? ?? 8b ?? ?? 8b ?? ?? 83 c7 04 8d ?? ?? e8 ?? ?? ?? ?? 8b ?? ?? 8d ?? ?? ?? bf 05 00 00 00 eb ??}

    condition:
        ( uint16(0) == 0x5a4d and
        ( 4 of them )
        ) or ( all of them )
}