They have also advised users to refrain from clicking on suspicious emails and regularly update the security patches on their PCs.

Amid repeated ransomware attacks, leading exchanges BSE and NSE have asked trading members to take urgent steps to safeguard their systems from Petya ransomware, which has impacted companies across the globe.

Earlier in May, the exchanges issued similar advisory about dreaded ransomware WannaCry that affected systems in over 100 countries.

Last week, Petya ransomware hit systems in several countries including Ukraine, Russia, the UK, the US, France, Germany, China and Japan.

Petya encrypts the files on infected Windows systems and spreads through malicious attachments to emails.

In separate circulars, the exchanges have advised members to update their Windows software, check security solutions and ensure they have back up and ransomware detection in place.

They have also advised users to refrain from clicking on suspicious emails and regularly update the security patches on their PCs.

They have also asked the brokers to follow the instructions issued by the government in this regard.

Besides, antivirus updates need to be pushed to all end users and servers.