Security researchers have discovered a “vaccine” for the huge cyber-attack that hit organisations across the world on Tuesday.
The creation of a single file can stop the attack from infecting a machine.
However, researchers have not been able to find a so-called kill switch that would prevent the crippling ransomware from spreading to other vulnerable computers.
Experts are still unsure about the attack’s origins or its real purpose.
Given that the ransom amount – $300 – was relatively small, some are speculating that the attack may be a front for causing wider disruption or making a political statement.
Among the victims of the attack were the Ukrainian central bank, Russian oil giant Rosneft, British advertising firm WPP and US law firm DLA Piper.
Also caught up in the attack was at least one hospital in the US city of Pittsburgh.
A perfc solution
But for those concerned about the attack there appears to be fix, albeit one with limited effectiveness.
By creating a read-only file – named perfc – and placing it within a computer’s “C:\Windows” folder, the attack will be stopped in its tracks.
An explanation of how to do this has been posted by security news website Bleeping Computer and has been backed up by several other security experts.
However, while this method is effective, it only protects the individual computer the perfc file is placed on. Researchers have so far been unable to locate a kill switch that would disable the ransomware attack entirely.