After a serious bug was found Saturday, the U.S. Department of Homeland Security is warning Americans not to use the Internet Explorer web browser until a fix is resolved.

The bug, found by FireEye Research Labs, an internet security software company in Milpitas, Calif., can attack users' browsers through the Adobe Flash system. 

The hackers behind this bug even have a name for the take-over campaign; they're calling it "Operational Cladenstine Fox".

"We are currently unaware of a practical solution to this problem," Department of Homeland Security's United States Computer Emergency Readiness Team said in a post Monday morning. 

One way users can try to prevent the bug is by disabling Flash in Internet Explorer. 

"The attack will not work without Adobe Flash," FireEye said. "Disabling the Flash plugin within IE will prevent the exploit from functioning." 

It's best however, for companies and individuals to avoid Internet Explorer completely. Those wishing to access the Internet should use alternate browsers like Mozilla Firefox, Safari or Chrome.

The bug is affecting Internet Explorer versions 6 through 11, and Microsoft knows of it. They are currently working on a fix for the bug but haven't been able to release one yet.

The way the bug works is by luring a user to a website with a Flash file that corrupts their computer's memory. The bug then uses a program within Internet Explorer that allows the attacker to take over the victim's computer. 

Over half of PC computers use a version of Internet Explorer that is involved in this bug.

Especially vulnerable are users who still run Windows XP. These users won't be able to receive patch updates or fixes as Microsoft has discontinued serving this version of Windows.

Microsoft is urging Internet Explorer users to visit their Safety & Security Center, enable firewalls, installing all software updates and installing antimalware software.