5 Signs Your Android Smartphone Is Infected With Malware

Guest author Catalin Cosoi is chief security strategist at Bitdefender.

Android malware seems to be spreading at a dizzying pace. In the second half of 2012 alone, Bitdefender found that Android malware spiked 292% from the first half of the year. This could pose a threat to millions of smartphone users worldwide.

Android malware is becoming harder to detect for the average smartphone user who pays little, if any, attention to security. Fortunately, most malware creators are not rocket scientists, and a user does not have to be a computer scientist to combat them.

Adding the following clues together could reveal the presence of malware:

1. Bad Battery Life

Android users who don’t perform a lot of battery straining activities have a good idea of how long their battery should last. Malware gives itself away when batteries mysteriously drain quicker than usual. That's usually due to adware, spam-like malware that shows app users an inordinate amount of ads. Continuously displaying aggressive adware will impact heavily on battery life.

Whether the malware is hiding in plain sight by pretending to be a regular application or trying to stay hidden from the user, abnormal battery drainage can often give away the presence of an Android infection.

2. Dropped Calls And Disruptions

Mobile malware can affect ongoing or incoming calls. Dropped calls or strange disruptions during a conversation could indicate the existence of mobile malware that is interfering. If you can't blame your mobile carrier, then some strand of mobile malware could be the culprit. Call your service provider to determine if the dropped calls are its fault. If it is not your carrier, it is possible that someone or something is trying to eavesdrop on conversations or perform other suspicious activities.

3. Inordinately Large Phone Bills

Android malware often infects devices and starts sending SMS (text) messages to premium-rated numbers. While these effects are easily seen in your phone bill, not all malware programs are obviously greedy. They may send an SMS message just once a month to avoid suspicions, or they may uninstall themselves after punching a serious hole in your budget. Whether you use a monthly plan or a pay-as-you-go subscription, checking your bill should make it easy to figure out such message-sending malware has found its way onto a device.

4. Data Plan Spikes

Malware that smuggles data from your device to a third-party can often be detected by an examination of your data plan bill. Significant changes in your download or upload patterns could be a sign that someone or something has control over your device. Setting up data meter quotas might help figure out if a device has been compromised by data broadcasting malware. It will also help dodge high phone bills.

5. Clogged Performance

Depending on device hardware specifications, malware infestation may cause serious performance problems as it tries to read, write or broadcast data from your smartphone. Anybody that has ever had a PC infected with malware should be familiar with this. Imagine rebooting a device several times a day because background-running malware consumes too much processing power to let apps work properly. Performance clogging is yet another sign that malware might be present on your device. Checking RAM (Random Access Memory) use or CPU load could reveal the presence of malware that’s actively running on the device. 

Stay Safe And Be Mindful

The Android versions most targeted by malware are the common ones - Gingerbread 2.3, Ice Cream Sandwich 4.0 and Jelly Bean 4.1. Android users with these builds have an 88% chance of having their mobile phone infected with malware according to the Android Developer Dashboard.

In the event that you do find yourself with malware on your Android, there are a couple of options. First, delete the offending app. Even if the app is deleted, malware may still linger. You may have to completely reset your smartphone by going into the settings menu and peforming a "factory reset," which will clear the memory of the device.

A variety of paid and free security apps are available in the Google Play Android app store to help prevent apps from doing bad things. If you use your Android smartphone for business, your IT department likely has security solutions to help you purge any malware. 

In general, it is wise to scrutinize each and every permission an Android app asks for – many apps ask for invasive permissions when they don’t need them. Even apps packed with aggressive adware have a knack for collecting more data than they would ordinarily need to perform adequately. Be sure to read your permissions before clicking “accept.”