Smartphone users, in particular Android OS users are becoming key targets for malware authors, according to mobile security firm Lookout. Highlights of their new report suggest that Android users are two and a half times more likely to encounter malware today than they were six months ago.

Lookout, creators of the mobile security app by the same name, have released their Mobile Threat Report based on data collected through their Mobile Threat Network. In the extensive report, the company claims that 30 percent of Android owners are likely to encounter a web-based threat on their device each year.

Furthermore, an estimated half million to one million people have already been affected by Android malware in the first half of 2011. Android app infection increased from 80 apps in January to over 400 apps in June.

Malware on smartphones is a real concern since many of us have integrated these devices into our daily life. Some threats include making charges via SMS messages, checking call history, reading incoming and outgoing messages, tracking location and more.

Malicious software creators have come up with some pretty clever tactics to mislead users into downloading infected content. One such method is called repackaging, where a malware writer takes a legitimate application, modifies the contents to include their code, then redistributes it to a download site or application marketplace. Lookout says that this was the most common means of attack in the first two quarters of 2011.

Another underhanded method is the misleading disclosure, where an app developer will intentionally "bury" information about an undesirable effect deep within an EULA (End User License Agreement). EULAs can span dozens of pages and hardly anyone actually reads them. Since the author disclosed everything about the app and the end user agreed to the terms, the app can't technically be considered malware.

Lookout does offer up some valuable tips to help keep your device safe. They suggest only downloading apps from a trusted source, such as a reputable app store or download website. Also, it's a good idea to set a passcode on your device in the event that it is lost or stolen. Keeping your smartphone up to date with the latest firmware release and downloading a mobile security tool can also help keep you out of harm's way.