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The Chinese state-sponsored group known as  UNC3886  has been found to exploit a zero-day flaw in VMware ESXi hosts to backdoor Windows and Linux systems. The VMware Tools authentication bypass vulnerability, tracked as  CVE-2023-20867  (CVSS score: 3.9), "enabled the execution of privileged commands across Windows, Linux, and PhotonOS (vCenter) guest VMs without authentication of guest credentials from a compromised ESXi host and no default logging on guest VMs," Mandiant  said . UNC3886 was  initially documented  by the Google-owned threat intelligence firm in September 2022 as a cyber espionage actor infecting VMware ESXi and vCenter servers with backdoors named VIRTUALPITA and VIRTUALPIE. Earlier this March, the group was  linked  to the exploitation of a now-patched medium-severity security flaw in the Fortinet FortiOS operating system to deploy implants on the network appliances and interact with the aforementioned malware. The threat actor has been described as a

Details have emerged about a now-patched actively exploited security flaw in Microsoft Windows that could be abused by a threat actor to gain elevated privileges on affected systems. The vulnerability, tracked as  CVE-2023-29336 , is rated 7.8 for severity and concerns an elevation of privilege bug in the Win32k component. "An attacker who successfully exploited this vulnerability could gain SYSTEM privileges," Microsoft  disclosed  in an advisory issued last month as part of Patch Tuesday updates. Avast researchers Jan Vojtěšek, Milánek, and Luigino Camastra were credited with discovering and reporting the flaw. Win32k.sys is a kernel-mode driver and an integral part of the Windows architecture, being responsible for graphical device interface (GUI) and window management. While the exact specifics surrounding in-the-wild abuse of the flaw is presently not known, Numen Cyber has deconstructed the patch released by Microsoft to craft a proof-of-concept ( PoC ) exploit

As work ebbs with the typical end-of-year slowdown, now is a good time to review user roles and privileges and remove anyone who shouldn't have access as well as trim unnecessary permissions. In addition to saving some unnecessary license fees, a clean user inventory significantly enhances the security of your SaaS applications. From reducing risk to protecting against data leakage, here is how you can start the new year with a clean user list.  How Offboarded Users  Still  Have Access to Your Apps When employees leave a company, they trigger a series of changes to backend systems in their wake. First, they are removed from the company's identity provider (IdP), which kicks off an automated workflow that deactivates their email and removes access to all internal systems. When enterprises use an SSO (single sign-on), these former employees lose access to any online properties – including SaaS applications – that require SSO for login.  However, that doesn't mean that former employee

Enterprise communications service provider 3CX confirmed that the  supply chain attack  targeting its desktop application for Windows and macOS was the handiwork of a threat actor with North Korean nexus. The findings are the result of an interim assessment conducted by Google-owned Mandiant, whose services were enlisted after the intrusion came to light late last month. The threat intelligence and incident response unit is tracking the activity under its uncategorized moniker  UNC4736 . It's worth noting that CrowdStrike has tied the attack to a Lazarus sub-group dubbed Labyrinth Chollima , citing tactical overlaps. The cybersecurity firm told The Hacker News the latest findings appear to be consistent with their previous attribution. The  attack chain , based on analyses from multiple security vendors, entailed the use of DLL side-loading techniques to load an information stealer known as ICONIC Stealer, followed by a second-stage called  Gopuram  in selective attacks aimed

A Chinese state-sponsored threat activity group tracked as  RedGolf  has been  attributed  to the use of a custom Windows and Linux backdoor called KEYPLUG. "RedGolf is a particularly prolific Chinese state-sponsored threat actor group that has likely been active for many years against a wide range of industries globally," Recorded Future told The Hacker News. "The group has shown the ability to rapidly weaponize  newly reported vulnerabilities (e.g. Log4Shell and  ProxyLogon ) and has a history of developing and using a large range of custom malware families." The use of KEYPLUG by Chinese threat actors was  first disclosed  by Google-owned Manidant in March 2022 in attacks targeting multiple U.S. state government networks between May 2021 and February 2022. Then in October 2022, Malwarebytes  detailed  a separate set of attacks targeting government entities in Sri Lanka in early August that leveraged a novel implant dubbed DBoxAgent to deploy KEYPLUG. Bot

Researchers have shed light on a new hybrid malware campaign targeting both Android and Windows operating systems in a bid to expand its pool of victims. The attacks entail the use of different malware such as  ERMAC ,  Erbium ,  Aurora , and  Laplas , according to a  ThreatFabric report  shared with The Hacker News. "This campaign resulted in thousands of victims," the Dutch cybersecurity company said, adding, "Erbium stealer successfully exfiltrated data from more then 1,300 victims." The ERMAC infections commence with a fraudulent website that claims to offer Wi-Fi authorization software for Android and Windows that, when installed, comes with features to steal seed phrases from crypto wallets and other sensitive data. ThreatFabric said it also found a number of malicious apps that were trojanized versions of legitimate apps like Instagram, with the operators using them as droppers to deliver the obfuscated malicious payload. The rogue apps, dubbed Zombin

The operators of the RansomExx ransomware have become the latest to develop a new variant fully rewritten in the Rust programming language, following other strains like  BlackCat ,  Hive , and  Luna . The latest version, dubbed RansomExx2 by the threat actor known as Hive0091 (aka DefrayX), is primarily designed to run on the Linux operating system, although it's expected that a Windows version will be released in the future. RansomExx, also known as Defray777 and Ransom X, is a  ransomware   family  that's known to be active since 2018. It has since been linked to a number of attacks on government agencies, manufacturers, and other high-profile entities like Embraer and GIGABYTE. "Malware written in Rust often benefits from lower [antivirus] detection rates (compared to those written in more common languages) and this may have been the primary reason to use the language," IBM Security X-Force researcher Charlotte Hammond  said  in a report published this week.

Details have emerged about a previously undocumented and fully undetectable (FUD) PowerShell backdoor that gains its stealth by disguising itself as part of a Windows update process. "The covert self-developed tool and the associated C2 commands seem to be the work of a sophisticated, unknown threat actor who has targeted approximately 100 victims," Tomer Bar, director of security research at SafeBreach,  said  in a new report. Attributed to an  unnamed threat actor , attack chains involving the malware commence with a weaponized  Microsoft Word document  that, per the company, was uploaded from Jordan on August 25, 2022. Metadata associated with the lure document indicates that the initial intrusion vector is a LinkedIn-based spear-phishing attack, which ultimately leads to the execution of a PowerShell script via a piece of embedded macro code. "The Macro drops 'updater.vbs,' creates a scheduled task pretending to be part of a Windows update, which will e

Details have emerged about a now-patched security flaw in Windows Common Log File System (CLFS) that could be exploited by an attacker to gain elevated permissions on compromised machines. Tracked as  CVE-2022-37969  (CVSS score: 7.8), the issue was addressed by Microsoft as part of its Patch Tuesday updates for September 2022, while also noting that it was being actively exploited in the wild. "An attacker must already have access and the ability to run code on the target system," the company  noted  in its advisory. "This technique does not allow for remote code execution in cases where the attacker does not already have that ability on the target system." It also credited researchers from CrowdStrike, DBAPPSecurity, Mandiant, and Zscaler for reporting the vulnerability without delving into additional specifics surrounding the nature of the attacks. Now, the Zscaler ThreatLabz researcher team has disclosed that it captured an in-the-wild exploit for the the

A previously undocumented command-and-control (C2) framework dubbed Alchimist is likely being used in the wild to target Windows, macOS, and Linux systems. "Alchimist C2 has a web interface written in Simplified Chinese and can generate a configured payload, establish remote sessions, deploy payload to the remote machines, capture screenshots, perform remote shellcode execution, and run arbitrary commands," Cisco Talos  said  in a report shared with The Hacker News. Written in GoLang, Alchimist is complemented by a beacon implant called Insekt, which comes with remote access features that can be instrumented by the C2 server. The discovery of Alchimist and its assorted family of malware implants comes three months after Talos also detailed another self-contained framework known as  Manjusaka , which has been  touted  as the "Chinese sibling of Sliver and Cobalt Strike." Even more interestingly, both Manjusaka and Alchimist pack in similar functionalities, desp

Tech giant Microsoft on Tuesday shipped fixes to quash  64 new security flaws  across its software lineup, including one zero-day flaw that has been actively exploited in real-world attacks. Of the 64 bugs, five are rated Critical, 57 are rated Important, one is rated Moderate, and one is rated Low in severity. The patches are in addition to  16 vulnerabilities  that Microsoft addressed in its Chromium-based Edge browser earlier this month. "In terms of CVEs released, this Patch Tuesday may appear on the lighter side in comparison to other months," Bharat Jogi, director of vulnerability and threat research at Qualys, said in a statement shared with The Hacker News. "However, this month hit a sizable milestone for the calendar year, with MSFT having fixed the 1000th CVE of 2022 – likely on track to surpass 2021, which patched 1,200 CVEs in total." The actively exploited vulnerability in question is  CVE-2022-37969  (CVSS score: 7.8), a privilege escalation flaw

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Tuesday added a recently disclosed security flaw in the UnRAR utility to its Known Exploited Vulnerabilities Catalog, based on evidence of active exploitation. Tracked as CVE-2022-30333 (CVSS score: 7.5), the issue concerns a path traversal vulnerability in the Unix versions of UnRAR that can be triggered upon extracting a maliciously crafted RAR archive. This means that an adversary could exploit the flaw to drop arbitrary files on a target system that has the utility installed simply by decompressing the file. The vulnerability was  revealed  by SonarSource researcher Simon Scannell in late June. "RARLAB UnRAR on Linux and UNIX contains a directory traversal vulnerability, allowing an attacker to write to files during an extract (unpack) operation," the agency  said  in an advisory. Although the flaw affects any Linux application that uses UnRAR to extract an archive file, a successful exploitation of

Microsoft on Monday announced the general availability of a feature called Autopatch that automatically keeps Windows and Office software up-to-date on enrolled endpoints. The launch, which comes a day before Microsoft is expected to release its monthly round of security patches, is available for customers with Windows Enterprise E3 and E5 licenses. It, however, doesn't support Windows Education (A3) or Windows Front Line Worker (F3) licenses. "Microsoft will continue to release updates on the second Tuesday of every month and now Autopatch helps streamline updating operations and create new opportunities for IT pros," Lior Bela  said . Autopatch works by  applying security updates  first to devices in what's called the Test ring, which contains a minimum number of representative devices. After a validation period, the updates are pushed to the First (1% devices), Fast (9%), and Broad (90%) rings. The service was first  teased  by the tech giant in April 2022

An unofficial security patch has been made available for a new Windows zero-day vulnerability in the Microsoft Support Diagnostic Tool (MSDT), even as the Follina flaw continues to be exploited in the wild. The issue — referenced as  DogWalk  — relates to a path traversal flaw that can be exploited to stash a malicious executable file to the Windows Startup folder when a potential target opens a specially crafted ".diagcab" archive file that contains a diagnostics configuration file. The idea is that the payload would get executed the next time the victim logs in to the system after a restart. The vulnerability affects all Windows versions, starting from Windows 7 and Server Server 2008 to the latest releases. DogWalk was originally  disclosed  by security researcher Imre Rad in January 2020 after Microsoft, having acknowledged the problem, deemed it as not a security issue. "There are a number of file types that can execute code in such a way but aren't techni

Cybersecurity researchers have discovered a new Windows malware with worm-like capabilities and is propagated by means of removable USB devices. Attributing the malware to a cluster named " Raspberry Robin ," Red Canary researchers  noted  that the worm "leverages Windows Installer to reach out to QNAP-associated domains and download a malicious DLL." The earliest signs of the activity are said to date back to September 2021, with infections observed in organizations with ties to technology and manufacturing sectors. Attack chains pertaining to Raspberry Robin start with connecting an infected USB drive to a Windows machine. Present within the device is the worm payload, which appears as a .LNK shortcut file to a legitimate folder. The worm then takes care of spawning a new process using cmd.exe to read and execute a malicious file stored on the external drive. This is followed by launching explorer.exe and msiexec.exe, the latter of which is used for extern

Researchers have exposed a new targeted email campaign aimed at French entities in the construction, real estate, and government sectors that leverages the Chocolatey Windows package manager to deliver a backdoor called  Serpent  on compromised systems. Enterprise security firm Proofpoint attributed the attacks to a likely advanced threat actor based on the tactics and the victimology patterns observed. The ultimate objective of the campaign remains presently unknown. "The threat actor attempted to install a backdoor on a potential victim's device, which could enable remote administration, command and control (C2), data theft, or deliver other additional payloads," Proofpoint researchers  said  in a report shared with The Hacker News. The phishing lure that triggers the infection sequence makes use of a resume-themed subject line, with the attached macro-embedded Microsoft Word document masquerading as information related to the European Union's General Data Prot

A new  cross-platform backdoor  called " SysJoker " has been observed targeting machines running Windows, Linux, and macOS operating systems as part of an ongoing espionage campaign that's believed to have been initiated during the second half of 2021. "SysJoker masquerades as a system update and generates its [command-and-control server] by decoding a string retrieved from a text file hosted on Google Drive," Intezer researchers Avigayil Mechtinger, Ryan Robinson, and Nicole Fishbein  noted  in a technical write-up publicizing their findings. "Based on victimology and malware's behavior, we assess that SysJoker is after specific targets." The Israeli cybersecurity company, attributing the work to an advanced threat actor, said it first discovered evidence of the implant in December 2021 during an active attack against a Linux-based web server belonging to an unnamed educational institution. A C++-based malware, SysJoker is delivered via a dr

Microsoft has rolled out  Patch Tuesday updates  to address multiple security vulnerabilities in Windows and other software, including one actively exploited flaw that's being abused to deliver Emotet, TrickBot, or Bazaloader malware payloads. The latest monthly release for December fixes a total of 67 flaws, bringing the total number of bugs patched by the company this year to 887, according to the  Zero Day Initiative . Seven of the 67 flaws are rated Critical and 60 are rated as Important in severity, with five of the issues publicly known at the time of release. It's worth noting that this is in addition to the  21 flaws  resolved in the Chromium-based Microsoft Edge browser. The most critical of the lot is  CVE-2021-43890  (CVSS score: 7.1), a Windows AppX installer spoofing vulnerability that Microsoft said could be exploited to achieve arbitrary code execution. The lower severity rating is indicative of the fact that code execution hinges on the logged-on user level,

Cybersecurity researchers on Wednesday took the wraps off a "simple yet remarkable" malware loader for malicious Windows binaries targeting Central Europe, North America and the Middle East. Codenamed " Wslink " by ESET, this previously undocumented malware stands apart from the rest in that it runs as a server and executes received modules in memory. There are no specifics available on the initial compromise vector and there are no code or operational overlaps that tie this tool to a known threat actor group. The Slovak cybersecurity firm noted that it has seen only a handful of detections in the past two years, suggesting that it could be used in highly-targeted cyber infiltrations. Wslink is designed to run as a service and can accept encrypted portal executable (PE) files from a specific IP address, which is then decrypted and loaded into memory prior to the execution. To achieve this, the client (i.e., the victim) and the server perform a handshake that in

Microsoft on Tuesday rolled out  security patches  to contain a total of 71 vulnerabilities in Microsoft Windows and other software, including a fix for an actively exploited privilege escalation vulnerability that could be exploited in conjunction with remote code execution bugs to take control over vulnerable systems. Two of the addressed security flaws are rated Critical, 68 are rated Important, and one is rated Low in severity, with three of the issues listed as publicly known at the time of the release. The four zero-days are as follows — CVE-2021-40449  (CVSS score: 7.8) - Win32k Elevation of Privilege Vulnerability CVE-2021-41335  (CVSS score: 7.8) - Windows Kernel Elevation of Privilege Vulnerability CVE-2021-40469  (CVSS score: 7.2) - Windows DNS Server Remote Code Execution Vulnerability CVE-2021-41338  (CVSS score: 5.5) - Windows AppContainer Firewall Rules Security Feature Bypass Vulnerability At the top of the list is CVE-2021-40449, a use-after-free vulnerability