Microsoft Exchange | Breaking Cybersecurity News | The Hacker News

The U.S. Department of Justice (DoJ) on Thursday announced charges against a 36-year-old Yemeni national for allegedly deploying the Black Kingdom ransomware against global targets, including businesses, schools, and hospitals in the United States. Rami Khaled Ahmed of Sana'a, Yemen, has been charged with one count of conspiracy, one count of intentional damage to a protected computer, and one count of threatening damage to a protected computer. Ahmed is assessed to be currently living in Yemen. "From March 2021 to June 2023, Ahmed and others infected computer networks of several U.S.-based victims, including a medical billing services company in Encino, a ski resort in Oregon, a school district in Pennsylvania, and a health clinic in Wisconsin," the DoJ said in a statement. Ahmed is accused of developing and deploying the ransomware by exploiting a vulnerability in Microsoft Exchange Server known as ProxyLogon. The ransomware worked by either encrypting data from ...

The threat actors behind the Medusa ransomware have claimed nearly 400 victims since it first emerged in January 2023, with the financially motivated attacks witnessing a 42% increase between 2023 and 2024. In the first two months of 2025 alone, the group has claimed over 40 attacks, according to data from the Symantec Threat Hunter Team shared with The Hacker News. The cybersecurity company is tracking the cluster under the name Spearwing. "Like the majority of ransomware operators, Spearwing and its affiliates carry out double extortion attacks, stealing victims' data before encrypting networks in order to increase the pressure on victims to pay a ransom," Symantec noted . "If victims refuse to pay, the group threatens to publish the stolen data on their data leaks site." While other ransomware-as-a-service (RaaS) players like RansomHub (aka Greenbottle and Cyclops), Play (aka Balloonfly), and Qilin (aka Agenda, Stinkbug, and Water Galura) have benefite...

For decades, Microsoft Exchange has been the backbone of business communications, powering emailing, scheduling and collaboration for organizations worldwide. Whether deployed on-premises or in hybrid environments, companies of all sizes rely on Exchange for seamless internal and external communication, often integrating it deeply with their workflows, compliance policies and security frameworks. However, Microsoft has officially announced that support for Exchange Server 2016 and Exchange Server 2019 will end on October 14, 2025. While this may seem like a distant concern, businesses and IT teams must start preparing now. The end of support means that Microsoft will no longer provide security patches, bug fixes or technical support, leaving organizations running on these versions exposed to security vulnerabilities, compliance risks and potential operational disruptions. So, what should businesses do now? In this article, we'll explore the impact of Microsoft's decision, the risks...

Not every security vulnerability is high risk on its own - but in the hands of an advanced attacker, even small weaknesses can escalate into major breaches. These five real vulnerabilities, uncovered by Intruder's bug-hunting team, reveal how attackers turn overlooked flaws into serious security incidents. 1. Stealing AWS Credentials with a Redirect Server-Side Request Forgery (SSRF) is a common vulnerability that can have a significant impact, especially in cloud-hosted applications. If a web application fetches resources from user-supplied URLs, care should be taken to ensure attackers can't manipulate requests to access unintended resources. While assessing a home-moving app running in AWS, our team tested common SSRF bypass techniques. The attack chain was as follows: the app sent a webhook request to the attacker's web server, which responded with a 302 redirect to AWS's metadata service. The app followed the redirect and logged the response, which exposed sensitive metadat...

U.S. telecoms giant T-Mobile has confirmed that it was also among the companies that were targeted by Chinese threat actors to gain access to valuable information. The adversaries, tracked as Salt Typhoon , breached the company as part of a "monthslong campaign" designed to harvest cellphone communications of "high-value intelligence targets." It's not clear what information was taken, if any, during the malicious activity. "T-Mobile is closely monitoring this industry-wide attack, and at this time, T-Mobile systems and data have not been impacted in any significant way, and we have no evidence of impacts to customer information," a spokesperson for the company was quoted as saying to The Wall Street Journal. "We will continue to monitor this closely, working with industry peers and the relevant authorities." With the latest development, T-Mobile has joined a list of major organizations like AT&T, Verizon, and Lumen Technologies that...

The Iranian threat actor known as OilRig has been observed exploiting a now-patched privilege escalation flaw impacting the Windows Kernel as part of a cyber espionage campaign targeting the U.A.E. and the broader Gulf region. "The group utilizes sophisticated tactics that include deploying a backdoor that leverages Microsoft Exchange servers for credentials theft, and exploiting vulnerabilities like CVE-2024-30088 for privilege escalation," Trend Micro researchers Mohamed Fahmy, Bahaa Yamany, Ahmed Kamal, and Nick Dai said in an analysis published on Friday. The cybersecurity company is tracking the threat actor under the moniker Earth Simnavaz , which is also referred to as APT34, Crambus, Cobalt Gypsy, GreenBug, Hazel Sandstorm (formerly EUROPIUM), and Helix Kitten. The attack chains entail the deployment of a previously undocumented implant that comes with capabilities to exfiltrate credentials through on-premises Microsoft Exchange servers, a tried-and-tested tact...

An unknown threat actor is exploiting known security flaws in Microsoft Exchange Server to deploy a keylogger malware in attacks targeting entities in Africa and the Middle East. Russian cybersecurity firm Positive Technologies said it identified over 30 victims spanning government agencies, banks, IT companies, and educational institutions. The first-ever compromise dates back to 2021. "This keylogger was collecting account credentials into a file accessible via a special path from the internet," the company  said  in a report published last week. Countries targeted by the intrusion set include Russia, the U.A.E., Kuwait, Oman, Niger, Nigeria, Ethiopia, Mauritius, Jordan, and Lebanon. The attack chains commence with the exploitation of  ProxyShell flaws  (CVE-2021-34473, CVE-2021-34523, and CVE-2021-31207) that were originally patched by Microsoft in May 2021. Successful  exploitation of the vulnerabilities  could allow an attacker to bypass authent...

The defense sector in Ukraine and Eastern Europe has been targeted by a novel .NET-based backdoor called  DeliveryCheck  (aka CAPIBAR or GAMEDAY) that's capable of delivering next-stage payloads. The Microsoft threat intelligence team, in  collaboration  with the Computer Emergency Response Team of Ukraine (CERT-UA), attributed the attacks to a Russian nation-state actor known as  Turla , which is also tracked under the names Iron Hunter, Secret Blizzard (formerly Krypton), Uroburos, Venomous Bear, and Waterbug. It's linked to Russia's Federal Security Service (FSB). "DeliveryCheck is distributed via email as documents with malicious macros," the company  said  in a series of tweets. "It persists via a scheduled task that downloads and launches it in memory. It also contacts a C2 server to retrieve tasks, which can include the launch of arbitrary payloads embedded in XSLT stylesheets." Successful initial access is also accompanied in some cases by...

Governmental entities in the Middle East and Africa have been at the receiving end of sustained cyber-espionage attacks that leverage never-before-seen and rare credential theft and Exchange email exfiltration techniques. "The main goal of the attacks was to obtain highly confidential and sensitive information, specifically related to politicians, military activities, and ministries of foreign affairs," Lior Rochberger, senior threat researcher at Palo Alto Networks,  said  in a technical deep dive published last week. The company's Cortex Threat Research team is  tracking  the activity under the temporary name  CL-STA-0043  (where CL stands for cluster and STA stands for state-backed motivation), describing it as a "true advanced persistent threat." The infection chain is triggered by the exploitation of vulnerable on-premises Internet Information Services ( IIS ) and Microsoft Exchange servers to infiltrate target networks. Palo Alto Networks said i...

An unnamed government entity associated with the United Arab Emirates (U.A.E.) was targeted by a likely Iranian threat actor to breach the victim's Microsoft Exchange Server with a "simple yet effective" backdoor dubbed  PowerExchange . According to a new report from Fortinet FortiGuard Labs, the intrusion relied on email phishing as an initial access pathway, leading to the execution of a .NET executable contained with a ZIP file attachment. The binary, which masquerades as a PDF document, functions as a dropper to execute the final payload, which then launches the backdoor. PowerExchange, written in PowerShell, employs text files attached to emails for command-and-control (C2) communication. It allows the threat actor to run arbitrary payloads and upload and download files from and to the system. The custom implant achieves this by making use of the Exchange Web Services ( EWS ) API to connect to the victim's Exchange Server and uses a mailbox on the server to...

Microsoft is urging customers to keep their Exchange servers updated as well as take steps to bolster the environment, such as enabling  Windows Extended Protection  and configuring  certificate-based signing  of PowerShell serialization payloads. "Attackers looking to exploit unpatched Exchange servers are not going to go away," the tech giant's Exchange Team  said  in a post. "There are too many aspects of unpatched on-premises Exchange environments that are valuable to bad actors looking to exfiltrate data or commit other malicious acts." Microsoft also emphasized mitigations issued by the company are only a stopgap solution and that they can "become insufficient to protect against all variations of an attack," necessitating that users install necessary security updates to secure the servers. Exchange Server has been proven to be a lucrative attack vector in recent years, what with a number of security flaws in the software weaponized as zero-d...

The threat actor known as  BackdoorDiplomacy  has been linked to a new wave of attacks targeting Iranian government entities between July and late December 2022. Palo Alto Networks Unit 42, which is tracking the activity under its  constellation-themed  moniker  Playful Taurus , said it observed the government domains attempting to connect to malware infrastructure previously identified as associated with the adversary. Also known by the names APT15, KeChang, NICKEL, and Vixen Panda, the Chinese APT group has a history of cyber espionage campaigns aimed at government and diplomatic entities across North America, South America, Africa, and the Middle East at least since 2010. Slovak cybersecurity firm ESET, in June 2021,  unpacked  the intrusions mounted by the hacking crew against diplomatic entities and telecommunication companies in Africa and the Middle East using a custom implant known as Turian. Then in December 2021, Microsoft  announc...

Threat actors affiliated with a ransomware strain known as Play are leveraging a never-before-seen exploit chain that bypasses blocking rules for ProxyNotShell flaws in Microsoft Exchange Server to achieve remote code execution (RCE) through Outlook Web Access ( OWA ). "The new exploit method bypasses  URL rewrite mitigations  for the  Autodiscover endpoint ," CrowdStrike researchers Brian Pitchford, Erik Iker, and Nicolas Zilio  said  in a technical write-up published Tuesday. Play ransomware, which first surfaced in June 2022, has been  revealed  to adopt many tactics employed by other ransomware families such as  Hive  and  Nokoyawa , the latter of which  upgraded to Rust  in September 2022. The cybersecurity company's investigations into several Play ransomware intrusions found that initial access to the target environments was not achieved by directly exploiting  CVE-2022-41040 , but rather through the OWA endpoi...

Microsoft on Friday  disclosed  it has made more improvements to the  mitigation method  offered as a means to prevent exploitation attempts against the newly disclosed unpatched security flaws in Exchange Server. To that end, the tech giant has revised the blocking rule in IIS Manager from ".*autodiscover\.json.*Powershell.*" to "(?=.*autodiscover\.json)(?=.*powershell)." The list of updated steps to add the URL Rewrite rule is below - Open IIS Manager Select Default Web Site In the Feature View, click URL Rewrite In the Actions pane on the right-hand side, click Add Rule(s)… Select Request Blocking and click OK Add the string "(?=.*autodiscover\.json)(?=.*powershell)" (excluding quotes) Select Regular Expression under Using Select Abort Request under How to block and then click OK Expand the rule and select the rule with the pattern: (?=.*autodiscover\.json)(?=.*powershell) and click Edit under Conditions Change the Condition input from {U...