Rigged Excel documents making the rounds

Bug affects Excel 2003 Service Pack 2, Excel Viewer 2003, Excel 2002, Excel 2000, and Excel 2004 for Mac

Security experts have warned that malicious Microsoft Excel documents are making the rounds via email, exploiting an unpatched Excel vulnerability that has been known publicly since January.

The attacks come as Microsoft prepares to release several critical patches affecting every supported version of Office. The patches are believed to include a fix for the Excel bug.

Security organization US-CERT issued a warning this week on a Trojan exploiting the Excel bug.

"This Trojan is circulating through email messages that contain attached Excel files," US-CERT said in an advisory. "Known file names for these attachments are OLYMPIC.XLS and SCHEDULE.XLS. These files may also contain Windows binary executables that can compromise an affected system."

Maarten Van Horenbeeck, handler with the SANS Institute's Internet Storm Center (ISC), confirmed the attacks and said SANS had been tracking several exploits over the last few days.

"It should be noted that the incidents we are aware of have been limited to a very specific targeted attack and were not widespread," Horenbeeck said in an advisory. "In total, we established approximately 21 reports of attacks using only 8 different files, from within the same two communities, so far."

Some of the sample Trojans connect back to a server to retrieve the IP address of the control server, Horenbeeck said.

Microsoft first acknowledged the unpatched bug in January, in Security Advisory 947563.

The bug affects Excel 2003 Service Pack 2, Excel Viewer 2003, Excel 2002, Excel 2000, and Excel 2004 for Mac, Microsoft said. Successful attacks give the attacker the same rights as the local user.

This week Microsoft plans to ship four "critical" security fixes. The number of security bulletins Microsoft plans to issue is substantially below last month's 11 but the Office-only nature of the updates is unusual.

Of the planned patches, one appears to be for an Excel file format flaw and a second also relates to the spreadsheet application, while the third deals with a bug in Office Web Components -- controls that let users publish spreadsheets, charts and databases to the web, then view that content once it's published.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Matthew Broersma

Techworld.com
Show Comments

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?