In late 2010, a new kind of computer worm attacked an Iranian nuclear facility and so altered the course of cyber warfare that the U.S. Senate Committee on Homeland Security and Governmental Affairs marked the attack as the beginning of a new era: The Age of Stuxnet.
And while the Stuxnet worm may be the most identifiable, ominous new threat to cyber security as the new year begins, security experts have predicted 2011 will also be a year of dynamic shifts in online threats in other areas, including social media and political "hacktivism."
Here are the top four security concerns that cyber experts see coming over the digital horizon:
Stuxnet was first discovered in July 2010 by a security firm in Belarus, but didn't make global headlines until months later when Iranian state media announced the Middle East nation had been the target of a coordinated attack.
The worm was "the first of its kind, written to specifically target mission-critical control systems running a specific combination of software and hardware," a Department of Homeland Security official told ABC News.
But experts said the worm is not limited to any single type of target and can be altered to attack several key components of any nation's infrastructure, from electricity grids to oil rigs.
"The idea that a piece of malicious code can target physical systems and create real-world impacts is something that's been speculated in the industry for quite some time and certainly was largely understood to be possible. Stuxnet was the first widespread implementation of that kind of attack," Ben Greenbaum, senior research manager for cyber security firm Symantec, told ABC News.
Symantec's number one prediction for 2011 was increased cyber attacks on critical infrastructures just like the nuclear facility in Iran, and Stuxnet is only the beginning.
In November's Senate Homeland Security Committee meeting, National Cybersecurity and Communications Integration Center director Sean McGurk said that beyond Stuxnet, the Department was also concerned hackers could make their own copycat versions of the worm to attack whatever infrastructures they like -- a task Greenbaum said would be "fairly trivial."
"Stuxnet was seen by most in the security industry, including Symantec, as a harbinger of things to come," Greenbaum said.
In the Senate meeting, committee chairman Senator Joe Lieberman said, "Stuxnet was the warning of a gathering storm. We ignore it at great peril."
Another recent online development that experts expect to see increase in 2011 was played out on an international scale at the end of 2010.
Shortly after the information sharing website WikiLeaks published a portion of over 250,000 classified U.S. diplomatic documents, the website's founder, Julian Assange, was arrested on sexual assault charges. While he was in custody in England, some major financial institutions including Mastercard, Paypal and Visa discontinued a service that was helping to raise money for Assange's defense.
Wikileaks' supporters shot back in an unprecedented manner: nearly 50,000 people downloaded simple programs used to launch a massive denial of service attacks against the companies they deemed at odds with Wikileaks.