Protective Layers: Securing Corporate Networks
With so many types of malware stalking the Internet, companies pile on their e-mail defenses.
Computerworld - When the Nimda worm struck in 2001, one of its many victims was the Virginia Hospital Center in Arlington. The worm crashed servers, erased data and forced VHC to hire a consultant.
"It deleted files and brought a couple of servers to their knees," says IT director Mark Rein, who joined VHC a year after Nimda struck. "We had to have a company come in and eradicate the virus."
Fortunately, the virus didn't attack patient data. But it did provide a wake-up call, making VHC aware that it needed better e-mail security. There wasn't a silver bullet that could stop all viruses andnearly as badspam, so VHC opted for multiple overlapping defenses.
Today, the hospital is protected by five layers of antivirus and antispam defenses: an e-mail relay and antivirus product called eSafe from Aladdin Knowledge Systems Ltd.; an antispam and antivirus device from MailFrontier Inc.; antivirus software from Symantec Corp. on the e-mail servers and desktops; and a Web filter from Websense Inc. to monitor HTTP traffic and prevent employees from accidentally downloading viruses from the Web.
Finally, the hospital uses a Juniper Networks Inc. intrusion-detection and-prevention product to alert IT staff to anomalies in network traffic or unauthorized software on the system.
Sound excessive? In this era of massive malware attacks, such multiple layers of defense are, in fact, not paranoid but prudent.
In a March report from Ferris Research in San Francisco, antivirus software vendors said that there were nearly 100,000 viruses in existence then and that the number is increasing each month. F-Secure Corp., a vendor of antivirus products in Helsinki, Finland, notes that the largest virus outbreak in 2004, MyDoom.A, churned out nearly 10% of global e-mail at its peak (see New e-mail worm breaks infection records ).

![]()
Image Credit: Joyce Hesselberth
![]()
Last fall, for example, the U.S. Department of Energy's Carlsbad, N.M., office was perplexed by a sudden flood of pop-up pornographic ads on employee PCs. "We couldn't understand how we were getting all this traffic from adult sites," says Paul DeVito, information systems site security manager.
His staff traced it to a weather site used by the DOE that had been hacked and was downloading X-rated adware to visitors' PCs.
Besides cutting productivity, adware and spyware can also cause computer problems and worse. "It can cause instability in PCs, operations to crash, slow performance," notes Chris Williams, a senior analyst at Ferris Research. "And it can log your keystrokes and report those back to a Web site, so your network log-in is being compromised."
Security Strategies



- Excel 2010 Cheat Sheet
- Register for this Computerworld Insider Cheat Sheet and gain access to hundreds of premium content articles, guides, product reviews and more.
- Overcome Top 7 Admin Challenges of Active Directory
- As Active Directory's role in the enterprise has drastically increased, so has the need to secure the data. Gain insight on creating repeatable,...
- Insiders Can Ruin Your Company. Take Action.
- Did you know that 80 percent of threats to an organization come from the inside? The threat from insiders is often overlooked in...
- Top Solutions and Tools to Prevent Devastating Malware
- Custom malware frequently goes undetected. According to Forrester Research, the best way to reduce risk of breach is to deploy file integrity monitoring...
- X-Ray of the PCI Process-4 Proactive Steps
- This white paper from Forrester Research Inc., helps break PCI into understandable components. Security and risk professionals will gain knowledge and insight into...
- Identity Governance: The Business Imperatives
- This white paper describes the business challenges and opportunities that are driving interest in Identity Governance while discussing considerations your organization should make... All Security White Papers
- Live Webcast
Playing Defense: Staying on Top of Your Disaster Recovery Game - When it comes to disaster recovery, rapidly growing data volumes, distributed computing models, and new technologies all combine to present an ever-changing playing...
- Introduction to VMware vCenter Site Recovery Manager 5
- Traditional disaster recovery solutions are often too expensive, complex and unreliable to meet business requirements. As a result, IT departments are hesitant to...
- The Top Ten Secrets to Avoiding SAN Performance Problems
- Maintaining peak performance while simultaneously addressing the root cause of SAN errors is challenging. Learn the most common SAN problems and explore new...
- Deduplication Without Compromise
- Go inside Quantum's scalable, high-performance, multi-protocol new DXi deduplication appliances, designed to make backup much more effective. Discover how the new future-proof DXi6700...
- Director of Disk Products Discusses DXi6700
- Discover how the new DXi 6700 series of deduplication appliances provide investment protection and a future-proof feature set, all while delivering fast, scalable,...
- Playing Defense: Staying on Top of Your Disaster Recovery Game
- When it comes to disaster recovery, rapidly growing data volumes, distributed computing models, and new technologies all combine to present an ever-changing playing... All Security Webcasts