Poison Texts Targeting Mobile Phones

While smartphones get in the news for security reasons related to mobile malware, it’s important that we not forget about the other means of attacking mobile phones. USA Today has a piece which notes that,

One type of poison text message involves tricking people into signing up for worthless services for which they get billed $9.99 a month. Another type lures them into doing a survey to win a free iPhone or gift card. Instead, the attacker gets them to divulge payment card or other info useful for identity-theft scams. “Malicious attacks have exploded well beyond e-mail, and we are very aware of their move to mobile,” says Jacinta Tobin, a board member of the Messaging Anti-Abuse Working Group, an industry group combating the problem.

This approach is really just phishing using text messages. It’s significant, but not necessarily something that we should get particularly jumpy about. The same article recognizes that “hackers are repurposing skills honed in the PC world to attacks on specific mobile devices. Particularly, handsets using Google’s Android operating system are frequently the target of hackers.” What is missing in the article is a recognition that text-based phishing can be made considerably more effective if an individual’s smartphone has already leaked considerable amounts of personal data to the attacker via a third-party application. This is the scenario we should be leery of.

Specifically: we can easily imagine a situation where a hostile application that has been installed on a smartphone acquires enough personal information that an attacker can engage in targeted spear phishing. By getting name, address, names of friends and family, places of employment, recent photos that are geotagged, and so forth, it is possible to trick individuals by text messages to ‘give up’ information. Moreover, by first compromising devices attackers can better target specific individuals based on how the phishermen have profiled device owners: they can be choosy and target those who would either be most vulnerable or best resourced. It’s the integration of two known modes of attack – phishing and compromising smart devices – that will be particularly devastating far in excess of either attack vector on its own.