Mobile security firm Lookout used information from more than 60 million global users to see which threats pose the greatest risk to mobile phone users, and they identified three categories: malware, chargeware and adware. Some of these are greater threats in other countries, but given our highly mobile society there are chances of exposure for everyone.

Malware can include programs like viruses, worms, Trojan horses, ransomware and spyware. It can come into a phone as active content, code or an executable script and seeks to steal user data, impact device performance and can even commit financial fraud. Chargeware is a form of malware that can corrupt a mobile device and then manipulates the user into purchasing programs or services without clearly notifying the user that this is occurring. Unsubscribing can often be difficult so the user incurs charges for as long as possible. Adware uses advertisements to generate revenue for the creator, interferes with the use of the phone and can sometimes collect excessive personal data.

Many computer users were introduced to ransomware, a type of malware, last year. That threat has grown exponentially (by 75%) and is now one of the top threats for mobile users in the U.S., U.K. and Germany. The programs lock users out of their phones and force them to pay a "ransom" in order to unlock the device. Some programs slow down the phone and its functions, while others like ScarePackage result in a complete loss of functionality and a financial loss if the victim elects to pay the ransom.

In their recently released 2014 Mobile Threat Report, Lookout identified several malware programs that users in the U.S. should be aware of:

1. NotCompatible – Lookout identified this Trojan as the top mobile threat in 2014 because it enables the operators "to harness a considerable mobile botnet to do their bidding" and allows hackers to send and receive traffic through the victim's phone. In one instance hackers used infected mobile devices to purchase large of blocks of tickets simultaneously to circumvent anti-fraud measures on ticketing websites.
2. ScarePackage – This program poses as an Adobe flash update. It scans the phone and says that it has found illicit content and then displays a counterfeit message from the FBI to coerce the owner into paying the ransom in order to regain control of the device and avoid criminal prosecution.
3. ScareMeNot – Like ScarePackage, this Trojan pretends to scan the phone for security issues and reports that it has found illicit content and the victim must pay a ransom to regain control of the device.
4. ColdBrother – Similar to ScarePackage and ScareMeNot, this program can also take a front-facing photo of the victims and coerces them into paying the ransom.
5. Koler – Disguised as a media app, Koler operates like the previously mentioned ransomware programs.

The endgame in all of this is what will bring in the most money for hackers. Ransomware programs can charge victims as much as several hundred dollars to unlock their phones. The best defense is to purchase apps from a legitimate app store. If something looks fishy, it probably is says Kevin Mahaffey, Lookout's co-founder and chief technology officer. Apps that ask for a lot of personal data should also be suspect.

While Lookout's report found that more Android devices were impacted than Apple products, the fact that there are more Android devices on the market and apps for them can be downloaded from a variety of sources may be why they experience a higher incidence of attacks. Apps for Apple products can only be downloaded through Apple's App Store, which has a more stringent review process.