The number of companies and organizations compromised by a security vulnerability in Microsoft Corp.’s SharePoint servers is increasing rapidly, with the tally of victims soaring more than six-fold in a few days,

A sweeping cyber-espionage campaign organization centered on vulnerable versions of Microsoft's server software has now claimed about 400 victims, according to researchers at Netherlands-based Eye Security.

More than 400 systems have been compromised so far in the widespread cyberattacks exploiting vulnerabilities in Microsoft SharePoint servers, according to researchers at Eye Security.