A University of Washington-led research team has won a $7.5 million, five-year Multidisciplinary University Research Initiative (MURI) grant from the Department of Defense to better model and mount defenses against stealthy, continuous computer hacking attacks known as "advanced persistent threats."

"Unlike conventional viruses, these threats exploit vulnerabilities and persist over a very long time and they're very difficult to detect," said principal investigator Radha Poovendran, chair of the UW Department of Electrical Engineering and director of the Network Security Lab, which he founded in 2001. "Right now, there is no good understanding of the interactions in these complex cyberattacks or how to mitigate them."

The winning proposal was one of 23 MURI awards announced Friday totaling $162 million, which support research by teams of investigators that span more than one traditional science and engineering discipline in order to accelerate research progress. The grants support basic research with significant potential to improve the nation's security or expand military capabilities.

The UW-led team will develop a new and comprehensive scientific framework to understand advanced persistent threats and mathematically represent adversarial cyber interactions. Using statistical modeling, adaptive game theory, machine learning and control and systems theory, they aim to model the strategic interactions between these stealthy malware attacks and cyber defense mechanisms to combat them.

One challenging characteristic of advanced persistent threats is that they consist of a collection of different types of attacks over time, which means that defense strategies also need to evolve. In addition, many variants may lead to the same composed attack.

The UW-led team will investigate and develop methods to determine how quickly the cyber environment changes and if a given defense can be effective within the rate of change of the cyber environment. In other words, they will analyze and quantify which side is "gaining" or "losing" cyber command at any given time, which helps the system know when to keep deploying a particular defense or switch to something else -- as well as the chances of success.

"The adversary and the system are always trying to outsmart each other -- in this way the interactions are essentially a game played between the system and adversary," said Poovendran. "But the economic game theory that most modeling methods are grounded in doesn't work well here. We are trying to develop a novel game theory framework that will significantly improve the results."

The highly competitive MURI program complements other DoD basic research efforts by supporting multidisciplinary teams with larger and longer awards in carefully chosen research topics identified for their potential for significant and sustained progress.

"Over the past 30 years, the DoD's MURI program has resulted in significant capabilities for our military forces and opened up entirely new lines of research," said Melissa L. Flagg, deputy assistant secretary of defense for research, in a news release announcing the awards.

"Examples include advances in laser frequency combs that have become the gold standard in frequency control for precision in navigation and targeting; atomic and molecular self-assembly projects that have opened new possibilities for nano-manufacturing; and the field of spintronics, which emerged from a MURI award on magnetic materials and devices research," she said.

The MURI team also includes UW co-investigator and electrical engineering associate professor Maryam Fazel and researchers from the University of California, Berkeley; the University of California, Santa Barbara; Georgia Tech and the University of Illinois. The award was granted through the Office of Naval Research. Initial research efforts were also funded by the National Science Foundation's Cyber-Physical Systems Program.