An anonymous reader writes Guests at hundreds of hotels around the world are susceptible to serious hacks because of routers that many hotel chains depend on for their Wi-Fi networks. Researchers have discovered a vulnerability in the systems, which would allow an attacker to distribute malware to guests, monitor and record data sent over the network, and even possibly gain access to the hotel's reservation and keycard systems. The vulnerability, which was discovered by Justin W. Clarke of the security firm Cylance, gives attackers read-write access to the root file system of the ANTlabs devices. The discovery of the vulnerable systems was particularly interesting to them in light of an active hotel hacking campaign uncovered last year by researchers at Kaspersky Lab. In that campaign, which Kaspersky dubbed DarkHotel.