Racked-Up Phone Bills
Last year, the SpamSoldier malware introduced the world to the first mobile SMS botnet. Designed specifically to spread to other phones using SMS messages, SpamSoldier also sent out huge amounts of offers hoping to monetize on its size. Other malware that takes advantage of text messaging has since arisen, much to the dismay of victims who are left to pore over enormous phone bills.
“Not all Trojans are so greedy,” warns Bitdefender. “They may sometimes send an SMS message once a month to avoid suspicions, or they may uninstall themselves after punching a serious hole in your budget.”
An outrageous phone bill is definitely indicative of mobile malware, but keeping a close watch on all your bills is a smart idea. Phantom credit card charges or mysterious subscription fees are a sign that something isn’t right.
Data Plan Spikes
Most malware doesn’t want to just sit on your phone, it either wants the data on your phone or it wants to use your phone to transmit information to somewhere else. This activity may come in the form of noticeable spikes on your data plan bill.
Fortunately, Android has some built in tools to help manage your data. From the settings menu, tap Data Usage in the Wireless & Networks section. From here you get an overview of how much data each app is using, and you can set a limit by tapping the “set mobile data limit” box and adjusting the sliders.
This is one of the harder symptoms to notice, since most mobile users have experienced some kind of battery issue their devices. However, Bitdefender notes that, “Malware can give itself away because batteries drain quicker than usual with such e-threats installed.”
This is because malware usually carries on its activities in the background, effectively making your device work double-time. If you notice your battery draining much faster than normal—particularly, with other symptoms listed here—your phone might carrying on activities without your knowledge.
Before you try downloading a battery optimization app, try to think if you’ve recently downloaded any unusual apps or received some suspicious messages. Or just give your phone a quick scan with your mobile security app of choice.
“Depending on device hardware specifications, malware infestation may cause serious performance problems as it tries to read, write, or broadcast data,” says Bitdefender. Like battery draining, poor performance can sometimes be difficult to notice, but might indicate that there are things going on behind the scenes.
A good way to check is through the settings menu, tapping on Apps, and swiping over to the Running section. Here, all your running apps are displayed alongside the amount of RAM they are using. It also shows you the amount of RAM available.
If you’re device is slowing down just because you’ve got a few too many apps, widgets, and live desktops running, then maybe you can’t blame malware for your troubles.
Dropped Calls and Disruptions
By its nature, malware isn’t always designed to play nice with the other functions of your phone. “Dropped calls or strange disruptions during a conversation might reveal the existence of mobile malware that’s interfering,” says Bitdefender.
Of course, many other factors might cause dropped or disrupted calls. Your location, problems with your carrier, and even space weather can affect cell phone calls. It’s a good idea to try and narrow down variables and see if the problem is consistent before assuming it’s malware.
What to Do Next?
If you’re seeing all or some of these symptoms on your phone, hopefully human error, the age of the device, or environmental factors can explain them away. If not, it’s probably time to bite the bullet and download security software.
It’s worth noting that many mobile security suites, like Kaspersky mobile security for Android, will actually scan apps as they’re downloaded, potentially preventing malware from ever getting onto your device. App reputation services can tell you whether or not an app is safe to install.
You can also head off malware infections by being wary of weird links, unsolicited emails with attachments, and SMS spam.
If you are infected, it’s not the end of the world. Most malware can be cleaned up in seconds, and affected user files restored from a backup of your mobile device. That is, of course, assuming you noticed the infection in the first place.