All the malware's attack vectors and infection spreads are not yet known, but we do know how to protect vulnerable systems.
Friday's ransomware outbreak is ongoing and while researchers work to stem the tide of infection, businesses, governments, and individuals can help the cause by making sure they have protected themselves.
The attack is due to a kind of ransomware called Wanna Decryptor, also known as WannaCrypt, WanaCrypt0r and WannaCry. The malware not only infects targets through traditional means -- such as phishing campaigns, malicious emails, and dodgy attachments -- but once a system has been infected, the malicious code scans for additional targets through networks and jumps to fresh victims.
When a system has been infected with WannaCrypt, the malware encrypts everything it can -- including the PC's hard drive and any connected devices, such as USB sticks and external storage devices.
The ransomware then locks users out of the system, throws up a landing page and demands a $300 ransom payment in the virtual currency Bitcoin in return for files to be unlocked. This amount then doubles within a few days if payment is not forthcoming. Users are also threatened with the mass deletion of files within a week if they resist paying.
If you've already been unfortunate enough to become infected with the ransomware do not give in and pay up. The threat actors behind WannaCrypt have already made roughly $43,000 from the campaign, but there is no guarantee that you will gain your files back if you do.
Instead, unless -- or until -- a decryption key is released by security experts, the best option is to hold tight or restore your system from a backup. Alternatively, businesses can reach out to security professionals to see if infections can be eradicated without damaging their systems.
In order to be protected against this threat, it is necessary to understand that the attack only impacts those running on older Windows operating systems.
A security fix was released in March which resolved the problem for Windows Vista, Windows Server 2008, Windows 7, Windows Server 2008 R2, Windows 8.1, Windows Server 2012, Windows 10, Windows Server 2012 R2, and Windows Server 2016, which are still supported.
If you are running these versions and have not downloaded Microsoft Security Bulletin MS17-010, you should do so now manually, or allow Windows Update to do the work for you.
If Windows Update has been enabled, then automatic updates will be applied. If not, you should re-enable the system and do not disable it again so you receive security fixes as soon as they are available for future threats.
Users of Windows 10 are not affected by the ransomware.
In response to the threat, Microsoft has also released an emergency patch for legacy Windows operating systems which, as out of cycle products, are no longer supported -- unless special support contracts are in place.
Security updates can be download and deployed manually for Windows Server 2003 SP2 x64, Windows Server 2003 SP2 x86, Windows XP SP2 x64, Windows XP SP3 x86, Windows XP Embedded SP3 x86, Windows 8 x86, and Windows 8 x64 directly from Microsoft.
Grab the necessary security updates here.
Microsoft has also added a signature to the Windows Defender antivirus to detect the ransomware.
If it is not possible to patch, as noted by security expert Troy Hunt, you should disable Windows' Server Messenger Block (SMBv1) to prevent WannaCrypt exploit.
Failing this, another alternative is to lock-down machines and prevent them accessing the Internet, or at least make sure network settings are as restricted as possible.
What the malware cannot reach, it cannot infect.
This should be a wake-up call for anyone and any business which still relies on antiquated operating systems which haven't been sold in decades. Threats which can cripped a business or destroy irreplaceable, personal content are real -- and security updates, however annoying, are important.
We are yet to see the full extent of how much damage WannaCrypt has caused and new variants have already been spotted, so if there's any time to update systems and get them to modern OS standards which are given regular security updates, it is now.