rule win_mailto_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2020-05-30"
        version = "1"
        description = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.4.0"
        tool_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.mailto"
        malpedia_rule_date = "20200529"
        malpedia_hash = "92c362319514e5a6da26204961446caa3a8b32a8"
        malpedia_version = "20200529"
        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 / approach 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 = { 8b4b10 85c9 743a 8b4314 85c0 7433 }
            // n = 6, score = 400
            //   8b4b10               | mov                 ecx, dword ptr [ebx + 0x10]
            //   85c9                 | test                ecx, ecx
            //   743a                 | je                  0x3c
            //   8b4314               | mov                 eax, dword ptr [ebx + 0x14]
            //   85c0                 | test                eax, eax
            //   7433                 | je                  0x35

        $sequence_1 = { 8d4878 a1???????? ff3406 8b01 ffd0 8b0d???????? 47 }
            // n = 7, score = 400
            //   8d4878               | lea                 ecx, [eax + 0x78]
            //   a1????????           |                     
            //   ff3406               | push                dword ptr [esi + eax]
            //   8b01                 | mov                 eax, dword ptr [ecx]
            //   ffd0                 | call                eax
            //   8b0d????????         |                     
            //   47                   | inc                 edi

        $sequence_2 = { 55 8b6c240c 56 8b03 f7e8 57 894500 }
            // n = 7, score = 400
            //   55                   | push                ebp
            //   8b6c240c             | mov                 ebp, dword ptr [esp + 0xc]
            //   56                   | push                esi
            //   8b03                 | mov                 eax, dword ptr [ebx]
            //   f7e8                 | imul                eax
            //   57                   | push                edi
            //   894500               | mov                 dword ptr [ebp], eax

        $sequence_3 = { 57 33ff 837c241cff 0f849d000000 8b742420 85f6 0f8491000000 }
            // n = 7, score = 400
            //   57                   | push                edi
            //   33ff                 | xor                 edi, edi
            //   837c241cff           | cmp                 dword ptr [esp + 0x1c], -1
            //   0f849d000000         | je                  0xa3
            //   8b742420             | mov                 esi, dword ptr [esp + 0x20]
            //   85f6                 | test                esi, esi
            //   0f8491000000         | je                  0x97

        $sequence_4 = { 8b44241c 5f c60100 8b4c241c }
            // n = 4, score = 400
            //   8b44241c             | mov                 eax, dword ptr [esp + 0x1c]
            //   5f                   | pop                 edi
            //   c60100               | mov                 byte ptr [ecx], 0
            //   8b4c241c             | mov                 ecx, dword ptr [esp + 0x1c]

        $sequence_5 = { e8???????? 83c40c 85c0 741a 8b4f14 56 51 }
            // n = 7, score = 400
            //   e8????????           |                     
            //   83c40c               | add                 esp, 0xc
            //   85c0                 | test                eax, eax
            //   741a                 | je                  0x1c
            //   8b4f14               | mov                 ecx, dword ptr [edi + 0x14]
            //   56                   | push                esi
            //   51                   | push                ecx

        $sequence_6 = { 6800040000 ff7344 e8???????? 83c408 8944241c 85c0 }
            // n = 6, score = 400
            //   6800040000           | push                0x400
            //   ff7344               | push                dword ptr [ebx + 0x44]
            //   e8????????           |                     
            //   83c408               | add                 esp, 8
            //   8944241c             | mov                 dword ptr [esp + 0x1c], eax
            //   85c0                 | test                eax, eax

        $sequence_7 = { 8b4348 f7e8 0fa4c201 03c0 898590000000 899594000000 5d }
            // n = 7, score = 400
            //   8b4348               | mov                 eax, dword ptr [ebx + 0x48]
            //   f7e8                 | imul                eax
            //   0fa4c201             | shld                edx, eax, 1
            //   03c0                 | add                 eax, eax
            //   898590000000         | mov                 dword ptr [ebp + 0x90], eax
            //   899594000000         | mov                 dword ptr [ebp + 0x94], edx
            //   5d                   | pop                 ebp

        $sequence_8 = { 8bc6 33c2 c1c007 89842488000000 89442460 8bc5 3384249c000000 }
            // n = 7, score = 400
            //   8bc6                 | mov                 eax, esi
            //   33c2                 | xor                 eax, edx
            //   c1c007               | rol                 eax, 7
            //   89842488000000       | mov                 dword ptr [esp + 0x88], eax
            //   89442460             | mov                 dword ptr [esp + 0x60], eax
            //   8bc5                 | mov                 eax, ebp
            //   3384249c000000       | xor                 eax, dword ptr [esp + 0x9c]

        $sequence_9 = { 56 c744241c00000000 0f844e020000 8b6c243c 85ed 0f8442020000 8b742440 }
            // n = 7, score = 400
            //   56                   | push                esi
            //   c744241c00000000     | mov                 dword ptr [esp + 0x1c], 0
            //   0f844e020000         | je                  0x254
            //   8b6c243c             | mov                 ebp, dword ptr [esp + 0x3c]
            //   85ed                 | test                ebp, ebp
            //   0f8442020000         | je                  0x248
            //   8b742440             | mov                 esi, dword ptr [esp + 0x40]

    condition:
        7 of them and filesize < 180224
}