Google Chrome Linux with Activity of Unknown Device

Question

I've recently noticed a strange comportment on my Google Chrome Browser with GMail, where suddenly appeared a connected Unknown Device, with a double connection and with the same IP than mine, looking at the GMail history Details of accesses, and I don't know where is the origin of the problem.

Illustration of the problem (Portuguese language location):

I've already deleted the Profile, following the below advice teached in the Ask Ubuntu Section:

https://askubuntu.com/questions/391858/clearing-all-private-user-data-from-chrome-from-the-command-line

*( Clearing all private user data from Chrome from the command line - Ask Ubuntu )

For the default Chrome configuration, run

 rm -rf ~/.config/google-chrome/Default/

and

rm -rf ~/.cache/google-chrome

, and the strange described problem doesn't gone yet until todays.

This below Topic, also doesn't help to resolve or remedy the problem:

<https://webapps.stackexchange.com/questions/105037/remove-access-for-unknown-devices-in-account-activity>

*( security - Remove access for unknown devices in account activity - Web Applications Stack Exchange )

. Maybe it's a viruse/malware on my Debian? I'll try to scan my computer, also verifying the Debian 7 Partition with ESET SysRescue:

<https://www.eset.com/int/support/sysrescue/>

, to know if I'll discover some infection, some trace of hidden prague on my system. I think that this symptom is uncommon and I suspect an infection, and it's the first time that I see this behavior on Linux.

Could someone here help me to investigate the problem? This might not be malware related, only Network issues on a last valid hypothesis. Only rests for me to let unoccupied an USB Flash Drive to make a Bootable AV USB Key for scan my computer, including the Bootable AVs as Kaspersky Rescue Disk or the ESET SysRescue Linux-based Security Distributions (the best Vaccines encountered on the market, according to all my searches).

Obs.: Maybe this is a prank of my older brother, accessing the Debian partition with Ubuntu and infecting it with a virus / malware. Or is it fruit of a infection of a possibly hidden extension on the latest 32-bit version of Google Chrome for Linux (.deb package), that was acquired when I was browsing on some harmful websites? I've not managed to encounter a guide with steps, and with a list of probable related causes for resolve the case.

Waiting a return as soon as possible.

Thanks.

@lhvf.

Answer 1

I assume you mean that the unknown device has your same home IP address -- so, not 192.168.x.y but something belonging, say, to Telecom Brasil.

If this is the case, the problem lies not in your Chrome browser or desktop Debian distribution, but in your home or nearby. Something is accessing your GMail account from your wireless Access Point, which implies it known the access codes for both.

The most likely explanation is that you have GMail on your WiFi-connected smartphone also.

Or you could have some "smart" device somewhere - an Android TV maybe - that's synchronized with your Google account.

Otherwise, it's someone else's device. This is, of course, potentially very bad. Try changing the passwords on both the account and the access point, using two different, robust, non-guessable passwords, ensure the access point is not vulnerable to some exploits (just google "BrandOfYourDevice exploit" or "BrandOfYourDevice security vulnerability"), it is not accessible from the outside, and is configured for WPA2 security.