An Israeli researcher was able to crack 70% of 5,000 WiFi networks in Tel Aviv, showing that home networks are extremely vulnerable and easy to hijack.

Ido Hoorvitch, a security expert at CyberArk, first roamed downtown with WiFi sniffing devices to collect about 5,000 network hashes for his research.

Next, the researcher tapped into a vulnerability that made it possible to find a PMKID hash that is normally used for roaming.

The PMKID hash leads to the compromising of the network’s SSID, the passphrase, the MAC address, and a static integer. The researcher collected PMKIDs that were to be cracked to derive the password via a previously discovered method from Jens “atom” Steube’s leading developer Hashcat.

In order to crack the passwords, all number options for Israeli phone numbers had to be calculated with ten digits, starting with 05, thus making it only eight digits.

Using this method, the researcher was able to crack 2,200 passwords at an average speed of nine minutes per password on a normal computer.

The next stage of the attack was a standard dictionary attack using the ‘Rockyou.txt’ dictionary, which led to a quick cracking of another 1359 passwords, most of which were lowercase.

In total, Hoorvitch cracked a staggering 70% of the passwords for the sampled WiFi networks. The research clearly shows that most people do not use strong passwords for their Wi-Fi networks, which puts them at high risk of being hacked.

Strong and secure passwords should be at least ten characters long and contain a combination of lower and upper case letters, as well as symbols and numbers. In addition, users are advised to disable both roaming and WPS because they are trading security for convenience.