Hackers are using phishing attacks to target internet routers and steal data, according to the security vendor Proofpoint.
Malicious emails purporting to be from Brazilian telecoms companies use dodgy URLs to in combination with known vulnerabilities on affected routers to hijack a person’s network, exploiting the fact that many people do not change passwords on their routers after they are set up.
Writing on its website, Proofpoint said: "This case is striking for several reasons, not the least of which is the introduction of phishing as the attack vector to carry out a compromise traditionally considered purely network-based.
"Like the farming practice of using fish remains as fertilizer, modern attackers are using phishing emails to improve the yields of their pharming campaigns [in other words, the mass theft of data]."
Victims who click the URLs are redirected to webpages that use cross-site request forgery to target the routers, brute forcing the admin login page by sending it HTTP requests until the correct credentials have been entered.
The hackers have also set up a backup service for their own domain name service (DNS) used in the attack, which comes into use if the primary malicious DNS is disrupted to avoid raising a victim’s suspicions.
"If the phishing email recipient clicks the link and the vulnerability is successfully exploited, any computer behind the hacked router (that is, anyone connecting wired or wirelessly to that router) would potentially have their computer query a malicious DNS server to lookup any hostname on the Internet," Proofpoint explained.
Once the attack has been carried out the hacker is able to eavesdrop on internet conversations, facilitating their access to confidential data, including "email communications, web sites, logins and passwords".
Despite the campaign currently targeting Brazilians, Proofpoint warned that the campaign is likely to spread beyond the South American country.
"The history of malware is the story of the spread of techniques from a local blip to global threat as attackers continually adopt new techniques that demonstrate their effectiveness against existing defences," it said.