I was playing around with Wireshark when I noticed something very suspicious: every time I open Firefox (official build from Ubuntu repos), it immediately connects to a server with an apparently random name like d2ddoduugvun08.cloudfront.net and sends some encrypted data.

I couldn't find anything specific on this domain, but it pops up on some malware sites.

At first I thought it was some Firefox telemetry server but it is disabled and the server is not a Mozilla server.

I deleted my ~/.mozilla folder, in case my profile was the problem, but the connection was still there every time.

At this point I thought my installation of Firefox was compromised, so I purged it and redownloaded it from the repos. The connection was still there.

I moved to another machine with Windows, and it doesn't make this connection; when I booted into an Ubuntu live USB, it does.

I decided to build Firefox from source and it does not make this connection.

I tried to use mitmproxy to intercept it but it ignores my system proxy settings.

So my question is: is this a legit thing added by Canonical? Is the Firefox package on Ubuntu compromised by some malware?


  • 4
    cloudfront.net is a cloud computing service, they're not likely to be involved directly in malware, any more than the bank that a mobster has his checking account in is involved in crime. – Barmar Oct 21 '19 at 18:10
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    Related, please see this question: unix.stackexchange.com/questions/363512/… – Rui F Ribeiro Oct 21 '19 at 20:50

It appears to be firefox heartbeat telemetry. It could be disabled in about:config settings (that particular one can probably be disabled with app.normandy.enabled=false in about:config)

If you do not like firefox phoning home (and elsewhere), there are also a few other settings you may want to change

  • Is that particular CloudFront distribution known to be associated with telemetry? – Matt Nordhoff Oct 22 '19 at 2:38

It appears to be from canonical as a whois check d2ddoduugvun08.cloudfront.net reveals the following:

Registrant Name: Legal Department
Registrant Organization: Amazon.com, Inc.
Registrant Street: PO BOX 81226
Registrant City: Seattle
Registrant State/Province: WA
Registrant Postal Code: 98108-1226
Registrant Country: US
Registrant Phone: +1.2062664064
Registrant Phone Ext: 
Registrant Fax: +1.2062667010
Registrant Fax Ext: 
Registrant Email: email@amazon.com
Registry Admin ID: 
Admin Name: Legal Department
Admin Organization: Amazon.com, Inc.

So it is not malware. This site is helpful https://www.whois.com/whois/

  • 1
    That's what I found too, but how do I disable it? Telemetry is disabled in the system settings. How do I know what is being sent? – botnet437 Oct 21 '19 at 5:24
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    "but how do I disable it? Telemetry is disabled in the system settings. How do I know what is being sent?" was not part of the original question. – DK Bose Oct 21 '19 at 6:14
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    How this helps to tell that this is not a malware? Anyone can rent servers from amazon. – JIV Oct 22 '19 at 7:06
  • 1
    Some would consider telemetry to be malware... – Federico Poloni Oct 22 '19 at 7:19
  • And amazon will just allow malware to be hosted on their servers @jiv – George Udosen Oct 23 '19 at 4:56

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