Since Friday May 12 a ransomware named WannaCrya has been affecting hundreds of thousands of machines and is still spreading today.
It encrypts all the data it finds, deletes the original files and demands a ransom payable in bitcoins for their return.

For Windows users

It’s more critical than ever that your Microsoft security updates are kept up to date and that backups are carried out.
In particular, make sure that these backups are not accessible via your Windows network.
Extreme caution should be exercised if you are using older versions of Windows (especially Windows XP, Windows Server 2003 or earlier).
On Friday, Microsoft released patches for these older versions, which are in principle no longer supported.
For more information: https://www.theguardian.com/technology/2017/may/12/global-cyber-attack-ransomware-nsa-uk-nhshttps://blogs.technet.microsoft.com/msrc/2017/05/12/customer-guidance-for-wannacrypt-attacks/

For Mac OS X users

Only Windows systems are affected.

Maximum caution with attachments

This virus is wreaking havoc despite the firewalls and other anti-virus software used by SMEs.
These technological tools are not infallible.
To protect yourself, there’s only one solution: NEVER open an e-mail attachment with a dubious extension or origin.

Backing up your data

It’s imperative to have backups of your files.
In the event of a ransomware infection, the last resort will be to restore files via your backups.
Obviously, these backups must not be on a network drive, as you would then have encrypted backups that would be unusable.
A reliable backup solution involves making an off-site backup (tapes, outsourced online backup, etc.).
If you have any doubts about your backup solution, don’t hesitate to contact us so that we can audit the solution you have in place.

Other rules not to be overlooked

  • Be equipped with a true professional antivirus software
  • Update your software and operating system regularly.
  • Use the administrator account only when really necessary
  • Limit user permissions on network shares
  • Limit the use of Office macros to certain groups of users who really need them
  • If in doubt, use a document viewer to open your attachments (rather than directly in Word or Excel).