vxCrypter Ransomware

vxCrypter is a recently observed .NET-based ransomware tool that has the capability to delete duplicate files on infected machines.

Threat ID:: CC-3002
Category:: Ransomware
Threat Severity:: Low
Threat Vector:
Published:: 5 April 2019 12:00 AM

Report a cyber attack: call 0300 303 5222 or email [email protected]

Summary

vxCrypter is a recently observed .NET-based ransomware tool that has the capability to delete duplicate files on infected machines.

Affected platforms

The following platforms are known to be affected:

Microsoft Windows

Microsoft Windows - All versions

Threat details

At the time of publication, the delivery method of vxCrypter is unknown as it was discovered in its development stage by a security researcher. As with most ransomware, it is likely to be delivered via spam campaigns.

Once installed, vxCrypter will attempt to encrypt all files matching a hard-coded extension list. During the encryption process, it will keep a record of the SHA256 file hash of each encrypted file and delete any further files that produce a previously encountered hash. vxCrypter will not delete duplicate encrypted files with certain extensions, such as .exe or .dll, but will delete files with the following extensions:

7z	cpp	h	key	ppt	sql	txt
asp	csv	hpp	mdb	pptx	sqlite	wmv
aspx	db	htm	mpeg	psd	sqlite3	xls
avi	doc	html	odt	py	sqlitedb	xlsx
bak	docx	java	pem	rar	tar	xml
bat	fla	jpeg	php	rb	tgz	xsd
bmp	flv	jpg	pl	reg	tif	zip
c	gif	jsp	png	sln	tiff

Remediation steps

Type	Step
	If a device on your network becomes infected with ransomware it will begin encrypting local machine files and files on any network the logged-in user has permission to access. For system administration accounts this may include backup storage locations. To avoid becoming infected with ransomware, ensure that: A robust program of education and awareness training is delivered to users to ensure they don’t open attachments or follow links within unsolicited emails. All operating systems, anti-virus and other security products are kept up to date. All day to day computer activities such as email and internet are performed using non-administrative accounts and that permissions are always assigned based on the principle of least privilege. Your organisation adopts a holistic all-round approach to Cyber Security as advocated by the 10 Steps to Cyber Security. Identifying the source of infection: Identifying the affected device and disconnecting or quarantining it from the network is essential to damage limitation. Users should immediately report infections to their IT support provider, disconnect their network cable and power the computer down. File auditing should be enabled, and file server logs should be monitored to detect signs of unauthorised encryption and allow the source of encryption to be identified (i.e. the infected device). To limit the damage of ransomware and enable recovery: All critical data must be backed up, and these backups must be sufficiently protected/kept out of reach of ransomware. Multiple backups should be created including at least one off-network backup (e.g. to tape). The only guaranteed way to recover from a ransomware infection is to restore all affected files from their most recent backup.

Type

Step

If a device on your network becomes infected with ransomware it will begin encrypting local machine files and files on any network the logged-in user has permission to access. For system administration accounts this may include backup storage locations.

To avoid becoming infected with ransomware, ensure that:

A robust program of education and awareness training is delivered to users to ensure they don’t open attachments or follow links within unsolicited emails.
All operating systems, anti-virus and other security products are kept up to date.
All day to day computer activities such as email and internet are performed using non-administrative accounts and that permissions are always assigned based on the principle of least privilege.
Your organisation adopts a holistic all-round approach to Cyber Security as advocated by the 10 Steps to Cyber Security.

Identifying the source of infection:
Identifying the affected device and disconnecting or quarantining it from the network is essential to damage limitation.

Users should immediately report infections to their IT support provider, disconnect their network cable and power the computer down.
File auditing should be enabled, and file server logs should be monitored to detect signs of unauthorised encryption and allow the source of encryption to be identified (i.e. the infected device).

To limit the damage of ransomware and enable recovery:
All critical data must be backed up, and these backups must be sufficiently protected/kept out of reach of ransomware.

Multiple backups should be created including at least one off-network backup (e.g. to tape).
The only guaranteed way to recover from a ransomware infection is to restore all affected files from their most recent backup.

Last edited: 14 February 2020 2:47 pm