The Information Commissioner's Office (ICO) is urging new mobile device users to be wary of downloading apps that could misuse their personal data.
The data protection watchdog said, with millions of people expected to receive new tablets and smartphones on Christmas Day, consumers need to take precautions before downloading apps onto their new devices.
Particularly when it comes to how the apps make use of people's personal information, the ICO warned.
There are a worrying number of outright malicious apps particularly on the Android platform.
Simon Rice, principal policy advisor for technology, said many apps process personal information without users realising.
"Apps do all sorts of weird and wonderful things...However, they often work by using personal information," said Rice.
"This can include information you would not normally choose to give out to a stranger, such as contact details or friends and relatives and details of your locations."
To protect against this, the ICO has published guidance about how to secure personal data on mobile devices.
For example, it urges users to only download apps from reputable sources, and not to ignore warnings about the information apps can access.
It also advises people to review the apps they use on a regular basis, and delete the ones they don't, and to consider downloading mobile security software.
Rice said app developers also have a duty to ensure their apps adhere to data protection and handling rules.
"Our guidance will help them achieve this by explaining the legal requirements when using personal information. That includes how to obtain lawful consent, the measures required to keep people's information secure and advice on carrying out routine testing and maintenance," he added.
"These are issues that must be considered at the start of the development process, but once addressed will help developers in the UK comply with the Data Protection Act and have the best chance of achieving commercial success."
Speaking to IT Pro, independent security expert Graham Cluley, said users should also be concerned about how well apps secure their data.
"The app makers may not have any malicious intentions, but that won't be much of a comfort if it turns out they have been careless with your security and your personal information has been exposed to online criminals," he said.
Despite the ICO's advice to only download apps from reputable sources, Cluley also warned users about the spread of malicious apps on official app stores.
For instance, apps that sign users up for premium rate phone lines or install unwanted ad pop ups have made their way onto official sites in the past.
"There are a worrying number of outright malicious apps particularly on the Android platform. Some of these, unfortunately, have managed to waltz past Google's security team and ended up distributed via the official Play store.
"I suspect most people would assume that any app available for download from the official Google Play store would be legitimate, but sadly some are designed to use dirty tricks to earn money."
