Up To 1.3m Computers Still At Risk From WannaCry Attack

Up to 1.3 million computers are thought to still be at risk following a major ransomware attack that infected more than 200,000 computers in 150 countries.

The 'WannaCry' attack affected the computer systems of the NHS, alongside Germany's railway system, Russia's interior ministry and major companies including Renault, FedEx, Telefonica and other.

It is understood that security experts believe that two new variants of the virus are already in circulation and the rate of infections are expected to escalate.

The virus's affect Windows operating systems , encrypting hard drives and servers and demanding payment to release the system.

Once a system is infected, the virus acts as a worm and spreads to all computers on that network.

The National Cyber Security Centre (NCSC) have issued guidance for businesses and organisations to deal with the cyber threat:

• Deploy patch MS17-010:

technet.microsoft.com/en-us/library/security/ms17-010.aspx

• A new patch has been made available for legacy platforms, and is available here:

blogs.technet.microsoft.com/msrc/2017/05/12/customer-guidance-for-wannacrypt-attacks

• If it is not possible to apply this patch, disable SMBv1.  There is guidance here:

support.microsoft.com/en-us/help/2696547

• and/or block SMBv1 ports on network devices [UDP 137, 138 and TCP 139, 445]

If these steps are not possible, propagation can be prevented by shutting down vulnerable systems.

Work done in the security research community has prevented a number of potential compromises. To benefit:

• Ensure that your systems can resolve and connect on TCP 80 to the domains below

www[.]iuqerfsodp9ifjaposdfjhgosurijfaewrwergwea[.]com

www[.]ifferfsodp9ifjaposdfjhgosurijfaewrwergwea[.]com

The NCSC said that unlike most malware infections, your IT department should not block these domains. Note that the malware is not proxy aware so a local DNS record may be required. This does not need to point to the internet, but can resolve to any accessible server which will accept connections on TCP 80.

Antivirus vendors are increasingly becoming able to detect and remediate this malware, therefore updating antivirus products will provide additional protection – though this will not recover any data that has already been encrypted.