rule win_plugx_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2020-08-17"
        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.plugx"
        malpedia_rule_date = "20200817"
        malpedia_hash = "8c895fd01eccb47a6225bcb1a3ba53cbb98644c5"
        malpedia_version = "20200817"
        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 = { 51 53 6a00 6a00 6a02 ffd0 85c0 }
            // n = 7, score = 1000
            //   51                   | push                ecx
            //   53                   | push                ebx
            //   6a00                 | push                0
            //   6a00                 | push                0
            //   6a02                 | push                2
            //   ffd0                 | call                eax
            //   85c0                 | test                eax, eax

        $sequence_1 = { 59 8bc8 e8???????? 8bc7 }
            // n = 4, score = 1000
            //   59                   | pop                 ecx
            //   8bc8                 | mov                 ecx, eax
            //   e8????????           |                     
            //   8bc7                 | mov                 eax, edi

        $sequence_2 = { 8b45fc 01470c 014710 01462c }
            // n = 4, score = 1000
            //   8b45fc               | mov                 eax, dword ptr [ebp - 4]
            //   01470c               | add                 dword ptr [edi + 0xc], eax
            //   014710               | add                 dword ptr [edi + 0x10], eax
            //   01462c               | add                 dword ptr [esi + 0x2c], eax

        $sequence_3 = { 55 8bec 51 0fb74612 }
            // n = 4, score = 1000
            //   55                   | push                ebp
            //   8bec                 | mov                 ebp, esp
            //   51                   | push                ecx
            //   0fb74612             | movzx               eax, word ptr [esi + 0x12]

        $sequence_4 = { 56 6a01 ff7508 56 e8???????? 59 }
            // n = 6, score = 1000
            //   56                   | push                esi
            //   6a01                 | push                1
            //   ff7508               | push                dword ptr [ebp + 8]
            //   56                   | push                esi
            //   e8????????           |                     
            //   59                   | pop                 ecx

        $sequence_5 = { 8945fc 3bc1 7c03 894dfc 8b4610 03462c ff75fc }
            // n = 7, score = 1000
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   3bc1                 | cmp                 eax, ecx
            //   7c03                 | jl                  5
            //   894dfc               | mov                 dword ptr [ebp - 4], ecx
            //   8b4610               | mov                 eax, dword ptr [esi + 0x10]
            //   03462c               | add                 eax, dword ptr [esi + 0x2c]
            //   ff75fc               | push                dword ptr [ebp - 4]

        $sequence_6 = { 53 33db 56 57 895de8 895df0 895dec }
            // n = 7, score = 1000
            //   53                   | push                ebx
            //   33db                 | xor                 ebx, ebx
            //   56                   | push                esi
            //   57                   | push                edi
            //   895de8               | mov                 dword ptr [ebp - 0x18], ebx
            //   895df0               | mov                 dword ptr [ebp - 0x10], ebx
            //   895dec               | mov                 dword ptr [ebp - 0x14], ebx

        $sequence_7 = { e8???????? 59 8bc8 e8???????? 8bc6 }
            // n = 5, score = 1000
            //   e8????????           |                     
            //   59                   | pop                 ecx
            //   8bc8                 | mov                 ecx, eax
            //   e8????????           |                     
            //   8bc6                 | mov                 eax, esi

        $sequence_8 = { 56 ffd0 33c0 5f 5e 5b 8be5 }
            // n = 7, score = 1000
            //   56                   | push                esi
            //   ffd0                 | call                eax
            //   33c0                 | xor                 eax, eax
            //   5f                   | pop                 edi
            //   5e                   | pop                 esi
            //   5b                   | pop                 ebx
            //   8be5                 | mov                 esp, ebp

        $sequence_9 = { 2b4f10 8945fc 3bc1 7c03 }
            // n = 4, score = 1000
            //   2b4f10               | sub                 ecx, dword ptr [edi + 0x10]
            //   8945fc               | mov                 dword ptr [ebp - 4], eax
            //   3bc1                 | cmp                 eax, ecx
            //   7c03                 | jl                  5

    condition:
        7 of them and filesize < 598016
}

rule win_plugx_w1 {
    meta:
        description = "PlugX Identifying Strings"
        author = "Seth Hardy"
        last_modified = "2014-06-12"
		source = "https://github.com/mattulm/sfiles_yara/blob/master/malware/plugx.yar"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.plugx"
        malpedia_version = "20170517"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
        
    strings:
        $BootLDR = "boot.ldr" wide ascii
        $Dwork = "d:\\work" nocase
        $Plug25 = "plug2.5"
        $Plug30 = "Plug3.0"
        $Shell6 = "Shell6"
      
    condition:
        $BootLDR or ($Dwork and ($Plug25 or $Plug30 or $Shell6))
}

rule win_plugx_w2 {
	meta:
		author = "Jean-Philippe Teissier / @Jipe_"
		description = "PlugX RAT"
		date = "2014-05-13"
		filetype = "memory"
		version = "1.0" 
		ref1 = "https://github.com/mattulm/IR-things/blob/master/volplugs/plugx.py"
		source = "https://github.com/mattulm/sfiles_yara/blob/master/malware/plugx.yar"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.plugx"
        malpedia_version = "20170517"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"
		
	strings:
		$v1a = { 47 55 4C 50 00 00 00 00 }
		$v1b = "/update?id=%8.8x" 
		$v1algoa = { BB 33 33 33 33 2B } 
		$v1algob = { BB 44 44 44 44 2B } 
		$v2a = "Proxy-Auth:" 
		$v2b = { 68 A0 02 00 00 } 
		$v2k = { C1 8F 3A 71 } 
		
	condition: 
		$v1a at 0 or $v1b or (($v2a or $v2b) and (($v1algoa and $v1algob) or $v2k))
}