The Weather Channel was knocked off the air Thursday morning by what it said was a malicious software attack on the network. The network’s morning show, “AMHQ,” which had been due to start at 6 a.m. ET, was unable to go on air. Instead viewers saw taped programming, “Heavy Rescue: 401.” The AMHQ show returned to the air at 7:39 a.m. ET with a commercial break, and at 7:43 a.m., its anchors announced the reason for their absence. “The Weather Channel, sadly, has been the victim of a malicious software attack today,” said anchor Jim Cantore. “Yes, and it has affected our ability to bring you your weather information,” added anchor Stephanie Abrams. “So we just wanted to say thank you again for your patience and we want to get right to today’s severe weather.” The network issued a statement saying that federal law enforcement is actively investigating the issue, and apologizing for any inconvenience to viewers.