Microsoft's Windows Phone emerged only partially scathed from this year's Mobile Pwn2Own hacking competition after a contestant failed to fully pierce its defenses.

A blog post from Hewlett-Packard, whose Zero Day Initiative organizes the contest, provided only sparse details. Nonetheless, the account appeared to show Windows phone largely surviving. An HP official wrote:

First, Nico Joly—who refined his competition entry on the very laptop he won at this spring’s Pwn2Own in Vancouver as part of the VUPEN team—was the sole competitor to take on Windows Phone (the Lumia 1520) this year, entering with an exploit aimed at the browser. He was successfully able to exfiltrate the cookie database; however, the sandbox held and he was unable to gain full control of the system.

No further details were immediately available. HP promised to provide more color about hacks throughout the two-day contest in the coming weeks, presumably after companies have released patches.

The Windows Phone attack came during day two of the mobile hacking contest. During day one, an iPhone 5S, Samsung Galaxy S5, LG Nexus 5, and Amazon Fire Phone were all fully hijacked. More details are here.