Android users face a new threat, a rogue app that tells all their friends they pirated the program, a Symantec security manager said today.
The app is a fake copy of the legitimate "Walk and Text," software that uses the smartphone's camera to show what's in front of the user while she simultaneously walks and texts.
Walk and Text is available not only on Google's official Android Market app store, but also on numerous file-sharing sites. It's one of several mobile apps created by Georgi Tanmazov, the CEO of Incorporate Apps.
On the Android Market, Walk and Text is priced at $1.54.
The Trojanized version of the app includes malicious code that pilfers personal data from the phone -- the phone number, the device's unique identifier and more -- and sends it to a remote anonymous server.
That's not new, said John Engles, a group product manager with Symantec's security response team. What is new, at least on mobile devices, is the rogue app's texting of an embarrassing 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!"
When the app is run, a final message appears on the smartphone's screen that states, "We really hope you learned something from this." That message is accompanied by a an offer to buy the legitimate program from the Android Market.
According to Symantec, the rogue app -- which the company pegged as "Android.Walkinwat" and identified as a Trojan horse -- is similar to other fake Android apps that host malware. "They took the legitimate app, decompiled it, added the malicious code, recompiled it and then placed it on small Android side markets," said Engles.
Although Engles said the Trojan maker's motivation was unclear, he said it was most likely created by anti-piracy vigilantes. But it's also possible that the creator of Android.Walkinwat wanted to undermine the reputation of the legitimate Walk and Text application.
Engles called Android.Walkinwat "fairly benign," in part because it doesn't appear to have elements common to other mobile malware, such as a backdoor that allows secret downloads of other code.
"And it doesn't seem to be very popular or widespread," said Engles. Symantec has classified the rogue app/Trojan as a "Low" threat.
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," said Engles.
Tanmazov, Walk and Text's developer, has denied any connection to the Trojan, and has threatened to sue AVAST Software, a Czech Republic-based security company that first blogged about the rogue version of his app more than a week ago.
In a message posted on the Web, Tanmazov accused AVAST of publicizing the Trojanized version of his app to promote their mobile security software.
"We wonder why only anti-piracy companies have interest in writing blogs about pirated apps they find on illegal sources and are trying to spread fear among the normal 'Android Market' customers," said Tanmazov.
In an e-mail reply to a request for comment, Tanmazov again denied any link to Android.Walkinwat and elaborated on his frustration that criminals had hijacked his reputation. "This is not the way we fight against piracy," Tanmazov said.
"[And] we have absolutely no control over anything other than what is on the Android Market. This file is all over the place now, Torrents, forums, and there is nothing we can do about it," said Tanmazov.
The real Walk and Text app on the Android Market does not contain the malicious code and features of the Trojanized Android.Walkinwat, Google confirmed today.
This isn't the first time that malware-filled Android apps have cropped up. Earlier this month, Google was forced to yank more than 50 infected applications from the Android Market.
Robert McMillan of the IDG News Service contributed to this report.
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 email@example.com.