Menu
Android ransomware 'Koler' turns into a worm, spreads via SMS

Android ransomware 'Koler' turns into a worm, spreads via SMS

The Koler ransomware locks the device screen and displays fake messages from police agencies

A malicious Android app that takes over the screen of devices and extorts money from users with fake notifications from law enforcement agencies was recently updated with a component that allows it to spread via text message spam.

Known as Koler, the ransomware Trojan has been on malware researchers' radar since May when it started being distributed through porn websites under the guise of legitimate apps. A new variant of the threat found recently by researchers from security firm AdaptiveMobile spreads through SMS messages that attempt to trick users into opening a shortened bit.ly URL.

Once installed on a device, Koler opens a persistent window that covers the entire screen and displays a fake message from local law enforcement agencies accusing users of viewing and storing child pornography. Victims are asked to pay a "fine" using MoneyPak prepaid cards in order to regain control of their phones.

The Koler ransomware is capable of displaying localized ransomware messages to users from at least 30 countries, including the U.S., where the impersonated law enforcement agency is the FBI.

The new version found by AdaptiveMobile sends a text message to all contacts in the victim's address book. The message reads: "someone made a profile named -[the contact's name]- and he uploaded some of your photos! is that you?" followed by a bit.ly URL.

The URL points to an Android application package file called IMG_7821.apk that's hosted on a Dropbox account. When installed, this application uses the name PhotoViewer, but is actually the ransomware program.

"Due to the Worm.Koler's SMS distribution mechanism, we are seeing a rapid spread of infected devices since the 19th of October, which we believe to be the original outbreak date," Yicheng Zhou, a security analyst at AdaptiveMobile, said in a blog post. "During this short period, we have detected several hundred phones that exhibit signs of infection, across multiple US carriers. In addition to this, other mobile operators worldwide -- predominantly in the Middle East, have been affected by this malware."

The best protection against ransomware threats like Koler is to have the "unknown sources" option turned off in the Android security settings menu. When this setting is disabled -- and it typically is by default -- users won't be able to install applications that are not obtained from the official Google Play store. Some users do turn this option on though, because there are legitimate applications that are not hosted on Google Play for various reasons.

Koler is not easy to uninstall through the regular application management menu because of the persistent window it keeps displaying over everything else that makes navigation impossible. Affected users should first reboot the device in safe mode and then uninstall the app, Zhou said.

Instructions on how to reboot the device in safe mode should be available in the phone's manual, but it generally involves pressing and holding the power button until the power menu appears, then taping and holding Power Off until the option to reboot in safe mode appears.

Follow Us

Join the New Zealand Reseller News newsletter!

Error: Please check your email address.

Tags AdaptiveMobilesecuritymobile securitymalware

Featured

Slideshows

Reseller News launches inaugural Hall of Fame lunch

Reseller News launches inaugural Hall of Fame lunch

Reseller News welcomed 2015 and 2016 inductees - Darryl Swann, Dave Rosenberg, Gary Bigwood, Keith Watson, Mike Hill and Scott Green - to the inaugural Reseller News Hall of Fame lunch, held at the French Cafe in Auckland. The inductees discussed how the channel can collectively work together to benefit New Zealand, the Kiwi skills shortage and the future of the industry. Photos by Maria Stefina.

Reseller News launches inaugural Hall of Fame lunch
Educating from the epicentre - Why distributors are the pulse checkers of the channel

Educating from the epicentre - Why distributors are the pulse checkers of the channel

​As the channel changes and industry voices deepen, the need for clarity and insight heightens. Market misconceptions talk of an “under pressure” distribution space, with competitors in that fateful “race for relevance” across New Zealand. Amidst the cliched assumptions however, distribution is once again showing its strength, as a force to be listened to, rather than questioned. Traditionally, the role was born out of a need for vendors and resellers to find one another, acting as a bridge between the testing lab and the marketplace. Yet despite new technologies and business approaches shaking the channel to its very core, distributors remain tied to the epicentre - providing the voice of reason amidst a seismic industry shift. In looking across both sides of the vendor and partner fences, the middle concept of the three-tier chain remains centrally placed to understand the metrics of two differing worlds, as the continual pulse checkers of the local channel. This exclusive Reseller News Roundtable, in association with Dicker Data and rhipe, examined the pivotal role of distribution in understanding the health of the channel, educating from the epicentre as the market transforms at a rapid rate.

Educating from the epicentre - Why distributors are the pulse checkers of the channel
Kiwi channel reunites as After Hours kicks off 2017

Kiwi channel reunites as After Hours kicks off 2017

After Hours made a welcome return to the channel social calendar last night, with a bumper crowd of distributors, vendors and resellers descending on The Jefferson in Auckland to kickstart 2017. Photos by Maria Stefina.

Kiwi channel reunites as After Hours kicks off 2017
Show Comments