rule win_ransomexx_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2020-12-22"
        version = "1"
        description = "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.ransomexx"
        malpedia_rule_date = "20201222"
        malpedia_hash = "30354d830a29f0fbd3714d93d94dea941d77a130"
        malpedia_version = "20201023"
        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 = { 88580c 8bcb 8bd3 c1e908 c1ea10 88480d 8b0d???????? }
            // n = 7, score = 100
            //   88580c               | mov                 byte ptr [eax + 0xc], bl
            //   8bcb                 | mov                 ecx, ebx
            //   8bd3                 | mov                 edx, ebx
            //   c1e908               | shr                 ecx, 8
            //   c1ea10               | shr                 edx, 0x10
            //   88480d               | mov                 byte ptr [eax + 0xd], cl
            //   8b0d????????         |                     

        $sequence_1 = { 8945e0 8b45d8 c1c00a 8945d8 8b45ec 3345f8 3345f0 }
            // n = 7, score = 100
            //   8945e0               | mov                 dword ptr [ebp - 0x20], eax
            //   8b45d8               | mov                 eax, dword ptr [ebp - 0x28]
            //   c1c00a               | rol                 eax, 0xa
            //   8945d8               | mov                 dword ptr [ebp - 0x28], eax
            //   8b45ec               | mov                 eax, dword ptr [ebp - 0x14]
            //   3345f8               | xor                 eax, dword ptr [ebp - 8]
            //   3345f0               | xor                 eax, dword ptr [ebp - 0x10]

        $sequence_2 = { 0345f4 8b5dcc 8945fc 8b45f8 c1c00a 8945f8 8b45d8 }
            // n = 7, score = 100
            //   0345f4               | add                 eax, dword ptr [ebp - 0xc]
            //   8b5dcc               | mov                 ebx, dword ptr [ebp - 0x34]
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   8b45f8               | mov                 eax, dword ptr [ebp - 8]
            //   c1c00a               | rol                 eax, 0xa
            //   8945f8               | mov                 dword ptr [ebp - 8], eax
            //   8b45d8               | mov                 eax, dword ptr [ebp - 0x28]

        $sequence_3 = { 895c0104 83c120 8954240c 83fa10 0f8cd3fdffff 83fa50 0f8df7000000 }
            // n = 7, score = 100
            //   895c0104             | mov                 dword ptr [ecx + eax + 4], ebx
            //   83c120               | add                 ecx, 0x20
            //   8954240c             | mov                 dword ptr [esp + 0xc], edx
            //   83fa10               | cmp                 edx, 0x10
            //   0f8cd3fdffff         | jl                  0xfffffdd9
            //   83fa50               | cmp                 edx, 0x50
            //   0f8df7000000         | jge                 0xfd

        $sequence_4 = { c1c802 33d8 235df8 897df4 335df0 c1c705 037dbc }
            // n = 7, score = 100
            //   c1c802               | ror                 eax, 2
            //   33d8                 | xor                 ebx, eax
            //   235df8               | and                 ebx, dword ptr [ebp - 8]
            //   897df4               | mov                 dword ptr [ebp - 0xc], edi
            //   335df0               | xor                 ebx, dword ptr [ebp - 0x10]
            //   c1c705               | rol                 edi, 5
            //   037dbc               | add                 edi, dword ptr [ebp - 0x44]

        $sequence_5 = { 0f84d5000000 33c0 8bff 6683bc45bcfdffff5c 750a }
            // n = 5, score = 100
            //   0f84d5000000         | je                  0xdb
            //   33c0                 | xor                 eax, eax
            //   8bff                 | mov                 edi, edi
            //   6683bc45bcfdffff5c     | cmp    word ptr [ebp + eax*2 - 0x244], 0x5c
            //   750a                 | jne                 0xc

        $sequence_6 = { c1c60a 33fe 8bf2 c1ce02 33fe 8b75dc 037df8 }
            // n = 7, score = 100
            //   c1c60a               | rol                 esi, 0xa
            //   33fe                 | xor                 edi, esi
            //   8bf2                 | mov                 esi, edx
            //   c1ce02               | ror                 esi, 2
            //   33fe                 | xor                 edi, esi
            //   8b75dc               | mov                 esi, dword ptr [ebp - 0x24]
            //   037df8               | add                 edi, dword ptr [ebp - 8]

        $sequence_7 = { 010e 114604 394604 770d 7204 390e 7307 }
            // n = 7, score = 100
            //   010e                 | add                 dword ptr [esi], ecx
            //   114604               | adc                 dword ptr [esi + 4], eax
            //   394604               | cmp                 dword ptr [esi + 4], eax
            //   770d                 | ja                  0xf
            //   7204                 | jb                  6
            //   390e                 | cmp                 dword ptr [esi], ecx
            //   7307                 | jae                 9

        $sequence_8 = { 8b70fc 33f1 894808 89700c 83fa28 0f8214feffff 5f }
            // n = 7, score = 100
            //   8b70fc               | mov                 esi, dword ptr [eax - 4]
            //   33f1                 | xor                 esi, ecx
            //   894808               | mov                 dword ptr [eax + 8], ecx
            //   89700c               | mov                 dword ptr [eax + 0xc], esi
            //   83fa28               | cmp                 edx, 0x28
            //   0f8214feffff         | jb                  0xfffffe1a
            //   5f                   | pop                 edi

        $sequence_9 = { 03fb 897808 8b780c 03f9 8b4814 03ce }
            // n = 6, score = 100
            //   03fb                 | add                 edi, ebx
            //   897808               | mov                 dword ptr [eax + 8], edi
            //   8b780c               | mov                 edi, dword ptr [eax + 0xc]
            //   03f9                 | add                 edi, ecx
            //   8b4814               | mov                 ecx, dword ptr [eax + 0x14]
            //   03ce                 | add                 ecx, esi

    condition:
        7 of them and filesize < 372736
}