DDoS crooks: Do you want us to blitz those phone lines too?
Cybercrooks are now offering to launch cyberattacks against telecom services, with prices starting at just $20 a day.
Distributed denial of attacks against websites or web services have been going on for many years. Attacks that swamped telecoms services are a much more recent innovation, first starting around 2010. While DDoS attacks on websites are typically launched from botnets (networks of compromised Windows PCs under the control of hackers), attacks on telecom lines are launched using attack scripts on compromised Asterisk (software PBX) server.
Default credentials are one of the main security weaknesses used by hackers to initially gain access to a VoIP/PBX systems prior to launching voice mail phishing scams or running SIP-based flooding attacks, say researchers.
Telecoms-focused denial of service attacks are motivated by the same sorts of motives as a DDoS on a website.
“Typical motives can be anything from revenge, extortion, political/ideological, and distraction from a larger set of financial crimes,” a blog post by Curt Wilson of DDoS mitigation experts Arbor Networks explains.
Many of the cybercrime techniques first seen while crooks blitzed websites with junk traffic are being reapplied in the arena of flooding phone lines as a prelude to secondary crimes, according to Arbor.
“Just as we’ve seen the Dirt Jumper bot used to create distractions – by launching DDoS attacks upon financial institutions and financial infrastructure at the same time that fraud is taking place (with the Zeus Trojan, or other banking malware or other attack technique) – DDoS aimed at telecommunications is being used to create distractions that allow other crimes to go unnoticed for a longer period.”
Arbor details an array of services offered by hackers, some of which offer to flood telephones (both mobile and fixed line) for $20 per day. The more cost-conscious would-be crooks can shop around for a service that offers to blitz lines for $5 an hour, the price offered in another ad spotted by the ASERT security research team.
As well as blitzing phone lines, other attacks against a targeted organisation’s VoIP system or SIP controllers are possible.
Poorly configured VoIP systems can be brought down even by something as simple as a port scan, Wilson notes.
“In such cases, an attacker could bring down an organisations’ phone system quickly if they were able to reach the controller. The benefits of proactive security testing can help identify such brittle systems ahead of time, before an attacker might latch onto the vulnerability.
“Any system is subject to availability attacks at any point where an application layer or other processor-intensive operation exists as well as the networks that supply these systems via link saturation and state-table exhaustion. Telecommunications systems are no exception to this principle, as we have seen. Clearly, there is money to be made in the underground economy or these services would not be advertised,” Wilson concludes. ®