Is there any risk to use the Tor Browser along with other programs (not using Tor)

Question

Please, could you tell me if my anonymity is at risk if I use the Tor Browser in the following scenarios:

1. I am using other browsers or programs (accessing the Internet, but not through Tor), while I am using the Tor Browser;

2. I am using a torrent client to download files (not through Tor), while I am using the Tor Browser;

3. I am uploading files using the Tor Browser;

4. I am downloading files using the Tor Browser (from cloud services, e-mails, file sharing services, other sites).

I use Windows, for that matter. Thank you very much!

Answer 1

Is my anonymity at risk in the following scenarios?

Not particularly, if you follow the basic guidelines.

1. I am using other browsers or programs (accessing the Internet, but not through Tor), while I am using the Tor Browser;

This shouldn't affect your anonymity: the traffic generated by the Tor Browser will go through the Tor network, while the traffic generated by the other browsers/programs will follow the regular path.

As I said, this shouldn't affect your anonymity: you must kept your identity using Tor and the one using the other browsers/programs separate!

Indeed, the information you provide while using the Tor Browser can be used to deanonymize you if it is correlated with the information the other browsers/programs provided. This means that you should avoid visiting the same websites, using the same accounts, etc.

Assume that you have two accounts on a website:

1. public_account -- this is your official account, the public one that you access through a regular browser, and any connection available.
2. private_account -- this is your secret account, the one you want to keep private, that you access only through Tor.

From a very restricted technical point of view (analyzing packets' content), your anonymity seems safe, as long as you don't send any information about yourself (or about public_account) with private_account. Unfortunately, analyzing the packets' content is not the only toy in the attacker's playset.

There are many scenarios possible, let us choose the one where the attacker is the website owner (or, the website has been compromised). The attacker knows:

• Your public_account;
• The fact that the private_account owner is using Tor.

It can be enough to break your anonymity if he does some statistical analysis¹ between the private_account and the others.

• It's strange, they are always connecting at the same time;
• private_account and public_account often interact together;
• private_account and public_account never interact together;
• etc.

It is very hard to blend in against statistics, because trying too hard can have an ironic effect.

A question has already been asked on the Information Security community, about using the Tor Browser and a regular one side by side; you can get more information by taking a look at it.

2. I am using a torrent client to download files (not through Tor), while I am using the Tor Browser;

Your torrent client is just a program accessing the Internet. See 1.

3. I am uploading files using the Tor Browser;

As usual, it depends of what you are uploading. Is there anything in or related to these files that could provide information on you?

The only thing the Tor Browser will give you is an anonymous way to upload the file.

4. I am downloading files using the Tor Browser (from cloud services, e-mails, file sharing services, other sites).

The Tor Browser won't protect you against what you have downloaded. Downloading files always creates a risk for you and your computer. Tor (and the Tor Browser) won't protect you against that.

In other words, any file you have downloaded can potentially be a malware that could deanonymize you, as well as it could encrypt all your file (ransomware), or do something else. This is independent of Tor.

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^{1 It is not about one or two specific point(s), it's about the whole.}

Answer 2

Please note that I'm a certified IT Tech and former Programmer, but not specialized in TOR Browser for Windows programming...

You asked Is my anonymity at risk in the following scenarios?

1.) I am using other browsers or programs (accessing the Internet, but not through Tor), while I am using the Tor Browser; Response: Yes, you may be at risk because of software "fingerprints", Any Browser Cookie sharing with non-Tor Browsers, and other "hints" (ie Window positioning coordinates, display fonts, etc.) could allow you to be tracked. Opening a TOR for Windows Browser session and Mozilla Firefox for Windows session at the same time can compromise your security due to Firefox Cookies (ie Google Cookies) that are temporarily loaded into "RAM" memory by Firefox and not TOR.

2.) I am using a torrent client to download files (not through Tor), while I am using the Tor Browser; Response: You are NOT anonymous whenever you use 3rd party software for uploads/downloads, even though you may have TOR software open. For example with TOR running, Bittorrent can show your IP address while open and downloading. This enables your Bittorrent IP to be checked by a 3rd Party to see if TOR ports and other software is also running.

3.) I am uploading files using the Tor Browser; Response: Any uploading/download of files while using TOR or other Browsers can reveal your IP address. Supposedly, use of Startpage/IXQuick is safe for VIEWING Search results (ie pics) through their Proxy Server & DOES NOT download the files that compromise your anonymity.

Startpage claims their website automatically changes the search keys assigned to each client every 15 minutes to discourage outside tracking. You should assume that searches completed without the Startpage Proxy or through most other 3rd Party websites (even though you are using TOR Browser) can be used to track where you go and what you search through either the website setup or use of 3rd Party Cookies loaded through other Browsers.

4.) I am downloading files using the Tor Browser (from cloud services, e-mails, file sharing services, other sites). Response: Any upload/download file transfer can be tracked and possibly traced, even when TOR is used to start the upload/download.

Third party Cloud Services try to log your IP address through several methods and may try to track or monitor where you go on the Internet for Security or Marketing purposes. Any website that requires you to login may compromise your anonymity through undisclosed IP logging & tracking.

For example, downloading a Adobe FLASH movie through TOR from a 3rd party website... Even though you do not view the FLASH movie itself - any upload/download to the Internet can automatically send marketing info to Adobe based on the uncompressed file type &/or extension. You should check Control Panel - Adobe Flash - Settings to disable Flash from sending info to Adobe without your knowledge or permission.

IMHO, Adobe is a sneaky company about loss of consumer privacy and this can directly affect TOR Browser use... Whenever you install an Adobe software update for ANY free or commercial Adobe product, Adobe automatically resets and turns on Internet tracking for applications and shares this and other info with Adobe without notifying you of the changes. These are some of the reasons why I always try to disable Adobe AIR and prevent other Adobe products from preloading during Startup. I only let Adobe notify me when software updates are available, not auto-install without my prior knowledge or permission & changing my settings without notice.