Hackers are exploiting a new, unpatched vulnerability in Microsoft Word that could allow them to take control of a victim’s computer, Symantec has warned.The zero-day vulnerability is the fourth in Microsoft’s widely used Word 2000 software that has not yet been patched, the security company said in its Security Response Weblog.A zero-day vulnerability refers to a security hole for which exploits are already available when it was discovered. This latest one affects most versions of Windows running Word, Symantec’s advisory said.Danish security vendor Secunia also reported the vulnerability and rated it as “extremely critical,” its highest-level warning. The attack comes via an infected Word document, a method increasingly used by hackers for targeted attacks. If the document is opened, it installs a Trojan horse program, called Trojan.Mdropper.W, onto the computer, Lau wrote. The Trojan also puts other files on a computer that enable a hacker to control it. Microsoft could not be immediately reached for comment. The company released three sets of critical patches on Jan. 9, including ones for Outlook, PowerPoint and Windows, but not for Word. Users can avoid trouble by not opening unexpected Word documents attached to e-mail. Hackers often spam out thousands of messages with harmful attachments, such as Trojan horse programs, hoping unsuspecting victims will open them.Trojans often look harmless and can quietly install themselves on a computer with no visible signs. The use of Word to mount an attack can be particularly effective since the file format is so widely used.-Jeremy Kirk, IDG News Service (London Bureau)Check out our CIO News Alerts and Tech Informer pages for more updated news coverage. Related content brandpost Rebalancing through Recalibration: CIOs Operationalizing Pandemic-era Innovation By Kamal Nath, CEO, Sify Technologies Jun 08, 2023 6 mins CIO Digital Transformation brandpost It’s time to evolve beyond marketing to create meaningful metaverse moments Insights on the results of the Protiviti and Oxford University survey: Executive Outlook on the Metaverse, 2033 and Beyond By Kim Bozzella Jun 08, 2023 6 mins Digital Transformation feature 10 hottest IT jobs for salary growth in 2023 The demand for tech workers hasn’t slowed down, as rising salaries reveal the most sought-after tech professionals for 2023, according to data from Dice. By Sarah K. White Jun 08, 2023 8 mins Salaries IT Jobs Careers interview Oshkosh CIO Anu Khare on IT’s pursuit of value The specialty truck maker’s IT chief sees tech-enabled transformation being fueled by a relentless focus on strategic fit and customer value — and passionate business involvement. By Dan Roberts Jun 08, 2023 9 mins Automotive Industry Manufacturing Industry IT Strategy Podcasts Videos Resources Events SUBSCRIBE TO OUR NEWSLETTER From our editors straight to your inbox Get started by entering your email address below. Please enter a valid email address Subscribe