Social media giant Twitter Inc, under an increased threat of regulation and plagued by serious security breaches, is appointing one of the world’s best-regarded hackers to tackle everything from engineering missteps to misinformation.

The company on Monday named Peiter Zatko, widely known by his hacker handle Mudge, to the new position of Head of Security, giving him a broad mandate to recommend changes in structure and practices. Zatko will report to CEO Jack Dorsey and is expected to take over the management of key security functions after a 45 to 60-day review.

Zatko gained recognition in the cybersecurity industry as a member of L0pht, a flamboyant Massachusetts-based hacking collective that famously warned Congress in 1998 about the insecurities of the internet. Zatko also oversaw high-profile cybersecurity projects at the Pentagon’s Defense Advanced Research and Projects Agency and did stints at Google and an independent lab for testing software integrity.

Zatko’scareer began in the 1990s when he simultaneously conducted classified work for a government contractor and was among the leaders of Cult of the Dead Cow, a hacking group notorious for releasing Windows hacking tools in order to goad Microsoft into improving security.

In an interview with Reuters, Zatko said he would take on security issues at Twitter ranging from information and physical security, to “platform integrity — which starts to touch on abuse and manipulation of the platform and engineering.”

Zatko is joining Twitter as the platform continues to deal with one of its greatest disinformation challenges yet — mitigating the effects of false claims of electoral fraud from outgoing President Donald Trump and his allies.