Microsoft Corp. warned on Tuesday of five new "critical"-rated security flaws in its Windows, Internet Explorer, Word and Messenger software programs that could allow attackers to take control of a personal computer.
The software maker issued software patches to fix the problems as part of its monthly security bulletin, which included three other security warnings, rated at the second-highest level of "important."
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Computer security experts urged users to download and install the patches, available at www.microsoft.com/security.
"Anything that's rated as a critical has the risk of someone being able to take over that machine completely," said Michael Sutton, Director at iDEFENSE Labs, the computer security company that worked with Microsoft to uncover three of the new vulnerabilities.
In addition to the vulnerabilities affecting Windows, Internet Explorer, Word and Messenger, Microsoft also issued a warning about a flaw affecting its Exchange Server software, used on networked computers to manage and store e-mail traffic.
Hackers could exploit the flaws to take control of a computer, allowing them to steal or delete information and also use infected computers as a base to launch further attacks.
Microsoft has been working for the last three years to improve the security and reliability of its software under its Trustworthy Computing initiative, as more and more malicious software targets weaknesses in Windows and other Microsoft software.