rule win_naikon_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-07-11"
        version = "1"
        description = "Detects win.naikon."
        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.naikon"
        malpedia_rule_date = "20230705"
        malpedia_hash = "42d0574f4405bd7d2b154d321d345acb18834a41"
        malpedia_version = "20230715"
        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 = { 8d9e80240110 803b00 8bcb 742c 8a5101 }
            // n = 5, score = 200
            //   8d9e80240110         | lea                 ebx, [esi + 0x10012480]
            //   803b00               | cmp                 byte ptr [ebx], 0
            //   8bcb                 | mov                 ecx, ebx
            //   742c                 | je                  0x2e
            //   8a5101               | mov                 dl, byte ptr [ecx + 1]

        $sequence_1 = { 6a00 57 895df8 e8???????? 56 8d8570fdffff 6a00 }
            // n = 7, score = 200
            //   6a00                 | push                0
            //   57                   | push                edi
            //   895df8               | mov                 dword ptr [ebp - 8], ebx
            //   e8????????           |                     
            //   56                   | push                esi
            //   8d8570fdffff         | lea                 eax, [ebp - 0x290]
            //   6a00                 | push                0

        $sequence_2 = { 57 ff35???????? ff15???????? f7d8 1bc0 5f f7d8 }
            // n = 7, score = 200
            //   57                   | push                edi
            //   ff35????????         |                     
            //   ff15????????         |                     
            //   f7d8                 | neg                 eax
            //   1bc0                 | sbb                 eax, eax
            //   5f                   | pop                 edi
            //   f7d8                 | neg                 eax

        $sequence_3 = { 83450804 8b1b 2b7d08 8d843dd4efffff 8b3d???????? 8906 8d4301 }
            // n = 7, score = 200
            //   83450804             | add                 dword ptr [ebp + 8], 4
            //   8b1b                 | mov                 ebx, dword ptr [ebx]
            //   2b7d08               | sub                 edi, dword ptr [ebp + 8]
            //   8d843dd4efffff       | lea                 eax, [ebp + edi - 0x102c]
            //   8b3d????????         |                     
            //   8906                 | mov                 dword ptr [esi], eax
            //   8d4301               | lea                 eax, [ebx + 1]

        $sequence_4 = { 8d45e0 53 50 8d4770 50 89759c c745a001000000 }
            // n = 7, score = 200
            //   8d45e0               | lea                 eax, [ebp - 0x20]
            //   53                   | push                ebx
            //   50                   | push                eax
            //   8d4770               | lea                 eax, [edi + 0x70]
            //   50                   | push                eax
            //   89759c               | mov                 dword ptr [ebp - 0x64], esi
            //   c745a001000000       | mov                 dword ptr [ebp - 0x60], 1

        $sequence_5 = { ff75fc e8???????? 8d0436 8903 50 8d8588f7feff 50 }
            // n = 7, score = 200
            //   ff75fc               | push                dword ptr [ebp - 4]
            //   e8????????           |                     
            //   8d0436               | lea                 eax, [esi + esi]
            //   8903                 | mov                 dword ptr [ebx], eax
            //   50                   | push                eax
            //   8d8588f7feff         | lea                 eax, [ebp - 0x10878]
            //   50                   | push                eax

        $sequence_6 = { 8bce 5f 57 6a4c e8???????? 57 }
            // n = 6, score = 200
            //   8bce                 | mov                 ecx, esi
            //   5f                   | pop                 edi
            //   57                   | push                edi
            //   6a4c                 | push                0x4c
            //   e8????????           |                     
            //   57                   | push                edi

        $sequence_7 = { ff15???????? 3bc6 894514 7540 ff75fc 8b1d???????? }
            // n = 6, score = 200
            //   ff15????????         |                     
            //   3bc6                 | cmp                 eax, esi
            //   894514               | mov                 dword ptr [ebp + 0x14], eax
            //   7540                 | jne                 0x42
            //   ff75fc               | push                dword ptr [ebp - 4]
            //   8b1d????????         |                     

        $sequence_8 = { 8b0c8d20320110 8d548104 8a4c8104 8ac1 2580000000 3974240c 7505 }
            // n = 7, score = 200
            //   8b0c8d20320110       | mov                 ecx, dword ptr [ecx*4 + 0x10013220]
            //   8d548104             | lea                 edx, [ecx + eax*4 + 4]
            //   8a4c8104             | mov                 cl, byte ptr [ecx + eax*4 + 4]
            //   8ac1                 | mov                 al, cl
            //   2580000000           | and                 eax, 0x80
            //   3974240c             | cmp                 dword ptr [esp + 0xc], esi
            //   7505                 | jne                 7

        $sequence_9 = { 57 e8???????? 83c414 8d440002 0106 }
            // n = 5, score = 200
            //   57                   | push                edi
            //   e8????????           |                     
            //   83c414               | add                 esp, 0x14
            //   8d440002             | lea                 eax, [eax + eax + 2]
            //   0106                 | add                 dword ptr [esi], eax

    condition:
        7 of them and filesize < 188416
}

/*
    This Yara ruleset is under the GNU-GPLv2 license (http://www.gnu.org/licenses/gpl-2.0.html) and open to any user or organization, as    long as you use it under this license.

*/

rule win_naikon_w0 {
    meta:
        description = "Naikon code features"
        author = "Seth Hardy"
        last_modified = "2014-06-25"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.naikon"
        malpedia_version = "20170618"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
    
    strings:
        // decryption
        $ = { 0F AF C1 C1 E0 1F } // imul eax, ecx; shl eah, 1fh
        $ = { 35 5A 01 00 00} // xor eax, 15ah
        $ = { 81 C2 7F 14 06 00 } // add edx, 6147fh
    
    condition:
        all of them
}

/*
    This Yara ruleset is under the GNU-GPLv2 license (http://www.gnu.org/licenses/gpl-2.0.html) and open to any user or organization, as    long as you use it under this license.

*/

rule win_naikon_w1 {
    meta:
        description = "Naikon Identifying Strings"
        author = "Seth Hardy"
        last_modified = "2014-06-25"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.naikon"
        malpedia_version = "20170618"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
        
    strings:
        $ = "NOKIAN95/WEB"
        $ = "/tag=info&id=15"
        $ = "skg(3)=&3.2d_u1"
        $ = "\\Temp\\iExplorer.exe"
        $ = "\\Temp\\\"TSG\""
        
    condition:
       any of them
}

rule win_naikon_w2 {
    meta:
        description = "Detects backdoors related to the Naikon APT"
        author = "Florian Roth"
        reference = "https://goo.gl/7vHyvh"
        date = "2015-05-14"
        hash = "d5716c80cba8554eb79eecfb4aa3d99faf0435a1833ec5ef51f528146c758eba"
        hash = "f5ab8e49c0778fa208baad660fe4fa40fc8a114f5f71614afbd6dcc09625cb96"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.naikon"
        malpedia_version = "20170618"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    strings:
        $x0 = "GET http://%s:%d/aspxabcdef.asp?%s HTTP/1.1" fullword ascii
        $x1 = "POST http://%s:%d/aspxabcdefg.asp?%s HTTP/1.1" fullword ascii
        $x2 = "greensky27.vicp.net" fullword ascii
        $x3 = "\\tempvxd.vxd.dll" fullword wide
        $x4 = "otna.vicp.net" fullword ascii
        $x5 = "smithking19.gicp.net" fullword ascii

        $s1 = "User-Agent: webclient" fullword ascii
        $s2 = "\\User.ini" fullword ascii
        $s3 = "User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-EN; rv:1.7.12) Gecko/200" ascii
        $s4 = "\\UserProfile.dll" fullword wide
        $s5 = "Connection:Keep-Alive: %d" fullword ascii
        $s6 = "Referer: http://%s:%d/" fullword ascii
        $s7 = "%s %s %s %d %d %d " fullword ascii
        $s8 = "%s--%s" fullword wide
        $s9 = "Run File Success!" fullword wide
        $s10 = "DRIVE_REMOTE" fullword wide
        $s11 = "ProxyEnable" fullword wide
        $s12 = "\\cmd.exe" fullword wide

    condition:
        uint16(0) == 0x5a4d and filesize < 1000KB and (1 of ($x*) or 7 of ($s*))
}