New Delhi, Mar 15 (IANS): Following the recently disclosed vulnerabilities in Microsoft business email servers, the hacking attempts on organisations using the services of those unpatched on-premises servers have multiplied by more than six times (or tripled) in the past 72 hours, a new report warned on Monday.

The country most attacked has been the US (21 per cent of all exploit attempts), followed by The Netherlands (12 per cent) and Turkey (12 per cent).

Most targeted industry sector has been government/military (27 per cent of all exploit attempts), followed by manufacturing (22 per cent), and then software vendors (9 per cent), according to Check Point Research.

"A full race has started among hackers and security professionals. Global experts are using massive preventative efforts to combat hackers who are working day-in and day-out to produce an exploit that can successfully leverage the remote code execution vulnerabilities in Microsoft Exchange," the researchers from the cyber security firm noted.

Amid reports indicating that about five different hacking groups are attacking the business email servers of Microsoft, the tech giant has detected a new family of ransomware.

Named as 'DearCry,' the new ransomware is "being used after an initial compromise of unpatched on-premises Exchange Servers," Microsoft said in a tweet last week. It uses the same four vulnerabilities that Microsoft linked to a new China-backed hacking group called "Hafnium".

On March 3, Microsoft released an emergency patch for its Exchange Server product, the most popular mail server worldwide. All incoming and outgoing emails, calendar invitations and virtually anything accessed within Outlook goes through the Exchange server.

Orange Tsai from DEVCORE, a security firm based in Taiwan, reported two vulnerabilities in January.

Unaware of the full magnitude of these findings, Microsoft was prompted to further investigate their Exchange server.

The investigation uncovered five more critical vulnerabilities.

The vulnerabilities allow an attacker to read emails from an Exchange server without authentication or accessing an individual's email account.

Further vulnerability chaining enables attackers to completely take over the mail server itself.

"If your organisation's Microsoft Exchange server is exposed to the internet, and if it has not been updated with the latest patches, nor protected by a third party software, then you should assume the server is completely compromised," warned Lotem Finkelsteen, Manager of Threat Intelligence, Check Point Software.

Right now, the purpose of the attack and what cybercriminals wanted within the network is still unknown.

"What we do know is that compromised servers could enable an unauthorized attacker to extract your corporate emails and execute malicious code inside your organisation with high privileges," he noted.