Microsoft has issued a warning about a serious security hole in its word processing program Microsoft Word. The company has yet to develop a security patch for the vulnerability.

According to Microsoft, opening a manipulated Word document can be enough to be a victim. There isn't a temporary technical solution to the problem at present so Microsoft advises against clicking on, or saving, any Word documents - even if they are sent from trusted sources.

The security hole is similar to previous vulnerabilites to have hit Microsoft Office applications in the past few months. An attacker could manipulate a Word file in a way that he/she would gain complete control over a vulnerable computer when the file is opened, Microsoft stated.

The vulnerability exists in Microsoft Word 2000, Microsoft Word 2002, Microsoft Office Word 2003, Microsoft Word Viewer 2003, Microsoft Word 2004 for Mac and Microsoft Word v.X for Mac.

The program suites in Microsoft Works 2004, 2005 and 2006 are also vulnerable since they include Microsoft Word.

Many security experts said they believe corporate espionage is the main motive behind the attacks. Anna Lagerkvist