Security News

The Conti ransomware gang is hacking into Microsoft Exchange servers and breaching corporate networks using recently disclosed ProxyShell vulnerability exploits. ProxyShell is the name of an exploit utilizing three chained Microsoft Exchange vulnerabilities that allow unauthenticated, remote code execution on unpatched vulnerable servers.

The massive attack on Microsoft Exchange servers in March may have been China harvesting information to train AI systems, according to US government officials and computer-security experts who talked to NPR. The plundering of these Exchange systems was attributed to Chinese government cyber-spies known as Hafnium; Beijing denied any involvement. It's said the crew exploited four zero-days in Redmond's mail software in a chain to hijack the servers and siphon off data.

Details have emerged about a now-patched security vulnerability impacting Microsoft Exchange Server that could be weaponized by an unauthenticated attacker to modify server configurations, thus leading to the disclosure of Personally Identifiable Information. The issue, tracked as CVE-2021-33766 and coined "ProxyToken," was discovered by Le Xuan Tuyen, a researcher at the Information Security Center of Vietnam Posts and Telecommunications Group, and reported through the Zero-Day Initiative program in March 2021.

Microsoft Exchange uses two websites; one, the front end, is what users connect to in order to access email. "The front-end website is mostly just a proxy to the back end. To allow access that requires forms authentication, the front end serves pages such as /owa/auth/logon.aspx," according to a Monday posting on the bug from Trend Micro's Zero Day Initiative.

Technical details have emerged on a serious vulnerability in Microsoft Exchange Server dubbed ProxyToken that does not require authentication to access emails from a target account. An attacker can exploit the vulnerability by crafting a request to web services within the Exchange Control Panel application and steal messages from a victim's inbox.

CISA is warning about a surge of ProxyShell attacks, as Huntress discovered 140 webshells launched against 1,900 unpatched Microsoft Exchange servers. Over the weekend, the Cybersecurity & Infrastructure Security Agency issued an urgent alert that attackers are actively attacking ProxyShell vulnerabilities in unpatched Microsoft Exchange Servers, joining researchers in urging organizations to immediately install the latest Microsoft Security Update.

The US Cybersecurity and Infrastructure Security Agency issued its first alert tagged as "Urgent," warning admins to patch on-premises Microsoft Exchange servers against actively exploited ProxyShell vulnerabilities. "Malicious cyber actors are actively exploiting the following ProxyShell vulnerabilities: CVE-2021-34473, CVE-2021-34523, and CVE-2021-31207," CISA warned over the weekend.

The U.S. Cybersecurity and Infrastructure Security Agency is warning of active exploitation attempts that leverage the latest line of "ProxyShell" Microsoft Exchange vulnerabilities that were patched earlier this May, including deploying LockFile ransomware on compromised systems. Tracked as CVE-2021-34473, CVE-2021-34523, and CVE-2021-31207, the vulnerabilities enable adversaries to bypass ACL controls, elevate privileges on the Exchange PowerShell backend, effectively permitting the attacker to perform unauthenticated, remote code execution.

The U.S. Cybersecurity and Infrastructure Security Agency is warning of active exploitation attempts that leverage the latest line of "ProxyShell" Microsoft Exchange vulnerabilities that were patched earlier this May, including deploying LockFile ransomware on compromised systems.Tracked as CVE-2021-34473, CVE-2021-34523, and CVE-2021-31207, the vulnerabilities enable adversaries to bypass ACL controls, elevate privileges on the Exchange PowerShell backend, effectively permitting the attacker to perform unauthenticated, remote code execution.

A new ransomware gang known as LockFile encrypts Windows domains after hacking into Microsoft Exchange servers using the recently disclosed ProxyShell vulnerabilities. ProxyShell is the name of an attack consisting of three chained Microsoft Exchange vulnerabilities that result in unauthenticated, remote code execution.