Outlook | Breaking Cybersecurity News | The Hacker News

Cybersecurity researchers have uncovered a new account takeover (ATO) campaign that leverages an open-source penetration testing framework called TeamFiltration to breach Microsoft Entra ID (formerly Azure Active Directory) user accounts. The activity, codenamed UNK_SneakyStrike by Proofpoint, has targeted over 80,000 user accounts across hundreds of organizations' cloud tenants since a surge in login attempts was observed in December 2024, leading to successful account takeovers. "Attackers leverage Microsoft Teams API and Amazon Web Services (AWS) servers located in various geographical regions to launch user-enumeration and password-spraying attempts," the enterprise security company said . "Attackers exploited access to specific resources and native applications, such as Microsoft Teams, OneDrive, Outlook, and others." TeamFiltration, publicly released by researcher Melvin "Flangvik" Langvik in August 2022 at the DEF CON security conference...

Microsoft has released security updates to address 51 flaws as part of its Patch Tuesday updates for June 2024. Of the 51 vulnerabilities, one is rated Critical and 50 are rated Important. This is in addition to 17 vulnerabilities resolved in the Chromium-based Edge browser over the past month. None of the security flaws have been actively exploited in the wild, with one of them listed as publicly known at the time of the release. This concerns a third-party advisory tracked as CVE-2023-50868 (CVSS score: 7.5), a denial-of-service issue impacting the DNSSEC validation process that could cause CPU exhaustion on a DNSSEC-validating resolver. It was reported by researchers from the National Research Center for Applied Cybersecurity (ATHENE) in Darmstadt back in February, alongside KeyTrap ( CVE-2023-50387 , CVSS score: 7.5). "NSEC3 is an improved version of NSEC (Next Secure) that provides authenticated denial of existence," Tyler Reguly, associate director of Security...

The threat actors behind the Windows-based  Grandoreiro  banking trojan have returned in a global campaign since March 2024 following a law enforcement takedown in January. The large-scale phishing attacks, likely facilitated by other cybercriminals via a malware-as-a-service (MaaS) model, target over 1,500 banks across the world, spanning more than 60 countries in Central and South America, Africa, Europe, and the Indo-Pacific, IBM X-Force said. While  Grandoreiro  is known primarily for its focus in Latin America, Spain, and Portugal, the expansion is likely a shift in strategy after attempts to  shut down its infrastructure  by Brazilian authorities. Going hand-in-hand with the broader targeting footprint are significant improvements to the malware itself, which indicates active development. "Analysis of the malware revealed major updates within the string decryption and domain generating algorithm (DGA), as well as the ability to use Mic...

A now-patched security flaw in Microsoft Outlook could be exploited by threat actors to access NT LAN Manager (NTLM) v2 hashed passwords when opening a specially crafted file. The issue, tracked as CVE-2023-35636 (CVSS score: 6.5), was addressed by the tech giant as part of its  Patch Tuesday updates  for December 2023. "In an email attack scenario, an attacker could exploit the vulnerability by sending the specially crafted file to the user and convincing the user to open the file," Microsoft  said  in an advisory released last month. "In a web-based attack scenario, an attacker could host a website (or leverage a compromised website that accepts or hosts user-provided content) containing a specially crafted file designed to exploit the vulnerability." Put differently, the adversary would have to convince users to click a link, either embedded in a phishing email or sent via an instant message, and then deceive them into opening the file in question. CVE-202...

Technical details have emerged about two now-patched security flaws in Microsoft Windows that could be chained by threat actors to achieve remote code execution on the Outlook email service sans any user interaction. "An attacker on the internet can chain the vulnerabilities together to create a full, zero-click remote code execution (RCE) exploit against Outlook clients," Akamai security researcher Ben Barnea, who discovered the vulnerabilities, said in a  two-part   report  shared with The Hacker News. The security issues, which were addressed by Microsoft in  August  and  October 2023 , respectively, are listed below - CVE-2023-35384  (CVSS score: 5.4) - Windows HTML Platforms Security Feature Bypass Vulnerability CVE-2023-36710  (CVSS score: 7.8) - Windows Media Foundation Core Remote Code Execution Vulnerability CVE-2023-35384 has been described by Akamai as a bypass for a critical security flaw that Microsoft patched in March 2023. T...

Microsoft on Monday said it detected Kremlin-backed nation-state activity exploiting a now-patched critical security flaw in its Outlook email service to gain unauthorized access to victims' accounts within Exchange servers. The tech giant  attributed  the intrusions to a threat actor it called  Forest Blizzard  (formerly Strontium), which is also widely tracked under the monikers APT28, BlueDelta, Fancy Bear, FROZENLAKE, Iron Twilight, Sednit, Sofacy, and TA422. The security vulnerability in question is  CVE-2023-23397  (CVSS score: 9.8), a critical privilege escalation bug that could allow an adversary to access a user's Net-NTLMv2 hash that could then be used to conduct a relay attack against another service to authenticate as the user. It was patched by Microsoft in March 2023. The goal, according to the Polish Cyber Command (DKWOC), is to obtain unauthorized access to mailboxes belonging to public and private entities in the country. "In the next...

Microsoft on Friday shared guidance to help customers discover indicators of compromise (IoCs) associated with a recently patched Outlook vulnerability. Tracked as CVE-2023-23397 (CVSS score: 9.8), the  critical flaw  relates to a case of privilege escalation that could be exploited to steal NT LAN Manager (NTLM) hashes and stage a  relay attack  without requiring any user interaction. "External attackers could send specially crafted emails that will cause a connection from the victim to an untrusted location of attackers' control," the company  noted  in an advisory released this month. "This will leak the  Net-NTLMv2 hash  of the victim to the untrusted network which an attacker can then relay to another service and authenticate as the victim." The vulnerability was resolved by Microsoft as part of its  Patch Tuesday updates  for March 2023, but not before Russia-based threat actors weaponized the flaw in attacks targeting gover...

Microsoft's Patch Tuesday update for March 2023 is rolling out with remediations for a set of  80 security flaws , two of which have come under active exploitation in the wild. Eight of the 80 bugs are rated Critical, 71 are rated Important, and one is rated Moderate in severity. The updates are in  addition to 29 flaws  the tech giant fixed in its Chromium-based Edge browser in recent weeks. The two vulnerabilities that have come under active attack include a Microsoft Outlook privilege escalation flaw ( CVE-2023-23397 , CVSS score: 9.8) and a Windows SmartScreen security feature bypass ( CVE-2023-24880 , CVSS score: 5.1). CVE-2023-23397 is "triggered when an attacker sends a message with an extended MAPI property with a UNC path to an SMB (TCP 445) share on a threat actor-controlled server," Microsoft  said  in a standalone advisory. A threat actor could leverage this flaw by sending a specially crafted email, activating it automatically when it is retrie...