The new Opera 9.64 fixes a number of problems, including one critical hole that viewing a specially crafted JPEG image could open. Another fix closes a risk of browser plug-ins launching data-stealing cross-domain-scripting attacks. See the . Click Help, Check for Updates to make sure you have the latest Opera version; if you don't, you must download and manually install the new version--an annoyance, but a worthwhile one.

Microsoft has fixed a similar flaw in Windows. Viewing a malicious Windows Metafile (WMF) or En­­hanced Metafile (EMF) image on a Web site or in an HTML e-mail could have let a bad guy run any command on a PC--a critical risk for Windows Vista, XP, 2000, Server 2003, and Server 2008. Get the fix via Automatic Up­­dates or .

Crooks have actively targeted a hole in Adobe Reader and Acrobat that victims can trigger by opening a malicious .pdf file distributed as an e-mail attachment.

Reader 9.1 and Acrobat 9.1 fix the hole; updates for the Windows, Macintosh, and Unix versions of the software are available. Adobe also released updates for those stuck with older versions of the software-Acrobat and Reader version 8.1.4 and 7.1.1 contain the fix. Click the usual Help, Check for Updates, or .