Antispam is another component of mobile device security. Antispam is the ability to identify and stop spam - typically in the form of e-mail - to the device, but for today’s mobile devices, the spam vectors increasingly include SMS as well. From your users’ perspective,a distinct difference between e-mail-based spam and text-messaging-based spam is the latter sometimes costs your users.

In response to this, carriers have been pretty active. In the United States, for instance, AT&T advertises a service called AT&T Smart Limits, which allows the user to block or allow text messages from certain users. Yes, it’s an opt-in, paid service that users have to subscribe to.

The other point is that there is a global uniformity component that needs to be factored in with any sort of solution you roll out. On the standards front, the GSMA (GSM Association), a consortium of nearly 800 members, has kick-started an initiative called GSM spam reporting service whereby users who receive spam can forward those messages to a standardized number. (It’s currently proposed as #7726, which spells SPAM on the handset.)

This is a neat way to build a database of blacklists for the spam operators and eventually use this information to build an in-network spam-blocking solution! Information about spammers will also be shared among participating members who will receive correlated reports with data on misuse and threat to their networks.

Antispam solutions - for e-mail or messaging - have more value if they're handled by the server rather than the client. This enables you to centralize the antispam solutions and apply remediation at the e-mail servers that you host - or apply it at your outsourced arm.

For SMS-based spamming, the service is typically provided by the carrier, so you should actively work with your user’s carrier, or educate your users about their carriers’ services, to arrive at a solution that satisfies your needs.

A new variant of mobile spam is the use of applications on the mobile device to expose a new threat vector. For example, the Facebook app on your users' devices is one of the most popular applications in use. Even though this isn't a mobile-specific spam vector, it's one that's growing in popularity using the social network applications for posting for spam and phishing attempts.

Facebook spam.
Facebook spam.

These kinds of social engineering-based spam are the hardest to mitigate and prevent, as these are predominantly tied to user behavior and tap into the psychology that the spammers become expert in exploiting.