Rogue Android app sent personal info to legit version's developer, claims AVAST

Developer denies he created the app to humiliate pirates

A malicious Android app that shamed users for pirating software transmitted personal information to a URL controlled by the legitimate app's developer, a security company said today.

The developer of "Walk and Text," the app whose code was recompiled and re-released on numerous file-sharing sites, denied the claim by AVAST Software, an anti-virus firm based in Prague.

Walk and Text, which costs $1.54 to download from the official Android Market, uses the smartphone's camera to show what's in front of users as they simultaneously walk and text, theoretically preventing them from slamming into signposts or stepping off curbs into traffic.

The Trojanized version of the app includes malicious code that texts an embarrassing anti-piracy message to each contact in the phone's address book.

"Hey, just downlaoded [sic] a pirated App off the Internet," the message reads. "Walk and Text for Android. Im [sic] stupid and cheap, it costed [sic] only 1 buck. Don't steal like I did!"

The rogue app -- which Symantec yesterday named "Android.Walkinwat" and identified as a Trojan horse -- also pilfers personal data from the phone, including the phone number and the device's unique identifier, and sends it to a remote server.

According to AVAST, that data was sent to a URL controlled by Georgi Tanmazov, the CEO of Incorporate Apps, and the developer of Walk and Text, as well as other Android apps.

"It was very obvious that the information went to his URL," said Vincent Steckler, the CEO of AVAST in an interview Friday. "Was there something receiving the information? [Tanmazov] said there was not. But from what we could see, yes, there was something there receiving the information."

Tanmazov flatly denied that he created the malicious version of Walk and Text.

"AVAST has indeed claimed there is a link to our servers, but there was no such file on our servers, and logs could probably prove this," said Tanmazov in an e-mail interview, also on Friday. "There is also no personal information being saved on our servers and this could also easily be proven."

Steckler said that he has yet to see that proof, and called on Tanmazov to share his server logs.

When asked if he would share the logs, Tanmazov agreed, but said he wasn't sure that such logs exist.

"The Web site is on a really cheap shared server and they delete stuff after three days I think," he said. "You understand that if we do have logs those are text files that could be altered so this will also not prove anything."

AVAST and Tanmazov have been at odds for more than a week, when AVAST blogged about the malicious version of Walk and Text that researchers found on the Internet.

Since then, Tanmazov has threatened to sue AVAST and accused the company of publicizing the Trojanized version of his app to promote its mobile security software. "We haven't heard from any lawyers," said Steckler. "But it's a common threat against security companies."

Today, Tanmazov said he was "still looking into options" that included a lawsuit, but acknowledged that the route would be expensive. "It is a very sorry situation that AVAST is trying to provoke us in such a way," he said.

Steckler denied that AVAST will shortly release a security app for Android, or warned users of the malicious edition of Walk and Text for publicity. "What we care about is malware out there that takes personal info and incurs costs to users," he said.

Installing the Trojanized app could result in higher texting bills, depending on the number of contacts in a victimized smartphone, and where those contacts lived. "This could cost you some money," John Engles, a group product manager with Symantec's security response team, said in an interview yesterday.

The back-and-forth between AVAST and Tanmazov is unusual, Steckler admitted.

"There's still a lot of private pushback from adware and spyware makers, which remains a very gray area. But this is the first case we know of where a developer of a legitimate app has gotten so angry. What makes this different is that data was being sent to his URL."

This isn't the first time that malware-filled Android apps have cropped up. Last month, Google yanked more than 50 infected applications from the Android Market. In that case, no complaints from the legitimate developers of those purloined apps surfaced publicly.

According to Google, Walk and Text on the Android Market does not contain the malicious code and features of the Trojanized copycat.

Hackers have turned to the tactic of taking a legitimate app, then recompiling it to include malware or malicious features because of Android's success, said Steckler.

And the practice won't stop anytime soon.

"This isn't a security deficiency of Android, but a philosophical choice by Google," said Steckler. "What makes Android so successful is also what makes it vulnerable here. Unlike the Apple ecosystem, Android is pretty much wide open, and users can get apps from almost anywhere."

Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer or subscribe to Gregg's RSS feed . His e-mail address is

Copyright © 2011 IDG Communications, Inc.

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