Microsoft Exchange users are now being targeted by ransom-seeking hackers, according to the latest findings from Microsoft Defender researchers.
The popular email server had been hit by at least ten hacking groups, including Chinese state-backed cyber criminals, who had taken advantage of four zero-day vulnerabilities.
Security program manager Philip Misner reported on Thursday that Exchange users now also need to watch out for “human-operated ransomware attacks”, with the threat to customers escalating as a result.
The ransomware, also known as DearCry, is typical in its approach, preventing users from being able to use their PCs or access their data until a payment is sent to hackers, according to information outlined by Microsoft.
“We have detected and are now blocking a new family of ransomware being used after an initial compromise of unpatched on-premises Exchange Servers,” Microsoft’s Security Intelligence team informed its Twitter followers.
This follows reports that a proof-of-concept tool to hack Microsoft Exchange servers has been published on Microsoft-owned GitHub.
Vietnam-based independent security researcher Nguyen Jang is believed to have shared the first functional public proof-of-concept exploit for a group of vulnerabilities in Microsoft Exchange servers known as ProxyLogon, according to reports by The Record.
RELATED RESOURCE
Managing security risk and compliance in a challenging landscape
How key technology partners grow with your organisation
A GitHub spokesperson told Vice that although “the publication and distribution of proof of concept exploit code has educational and research value to the security community”, its “goal is to balance that benefit with keeping the broader ecosystem safe”.
“In accordance with our Acceptable Use Policies, we disabled the gist following reports that it contains proof of concept code for a recently disclosed vulnerability that is being actively exploited,” they added.
Although the code was removed from GitHub mere hours after, its publishing could have still exacerbated an already dire situation for Exchange users.
Among the hundreds of thousands of victims are high-profile and political organisations such as the Norwegian government, which earlier this week reported that it had data stolen as a result. Reuters reported that up to 60,000 networks remain vulnerable in Germany alone.
Microsoft has advised on-premises Exchange Server customers to prioritise the security updates outlined here.
-
Driving change to shape the future of the industryOpinion Companies like TeamViewer are lending their support to encourage more female representation in STEM in traditionally male-dominated fields like motorsports…
-
Dreamforce 2025 live: All the news and updates from on the ground in San FranciscoNews We're live on the ground in San Francisco for Dreamforce 2025 – keep tabs on all of our rolling coverage from the annual Salesforce conference.
-
The number of ransomware groups rockets as new, smaller players emergeNews The good news is that the number of victims remains steady
-
Teens arrested over nursery chain Kido hacknews The ransom attack caused widespread shock when the hackers published children's personal data
-
NCA confirms arrest after airport cyber disruptionNews Disruption is easing across Europe following the ransomware incident
-
Cyber professionals are losing sleep over late night attacksNews Hackers are biding their time and launching attacks when businesses can’t respond
-
Prolific ransomware operator added to Europe’s Most Wanted list as US dangles $10 million rewardNews The US Department of Justice is offering a reward of up to $10 million for information leading to the arrest of Volodymyr Viktorovych Tymoshchuk, an alleged ransomware criminal.
-
Jaguar Land Rover “did the right thing” shutting down systems to thwart cyber attackNews The attack on Jaguar Land Rover highlights the growing attractiveness of the automotive sector
-
Ransomware attack on IT supplier disrupts hundreds of Swedish municipalitiesNews The attack on IT systems supplier Miljödata has impacted public sector services across the country
-
A notorious hacker group is ramping up cloud-based ransomware attacksNews The Storm-0501 threat group is refining its tactics, according to Microsoft, shifting away from traditional endpoint-based attacks and toward cloud-based ransomware.
