Security Market Segment LS
Wednesday, 07 June 2017 09:49

NSA document leaker identified by printer dot pattern Featured


A contractor who leaked a top-secret document to The Intercept was identified because the NSA was able to track who had printed out the document, using the yellow dot pattern that many printers place on documents, giving the time and date when the document was printed.

The Intercept ran its story on Monday and posted the document online; the arrest and charging of Reality Leigh Winner, 25, was announced by the Department of Justice the same day.

A detailed explanation of how she was tracked down was provided by Errata Security which pointed out that the document posted by The Intercept was a PDF containing the original printed version that had been scanned in.

"The problem is that most new printers print nearly invisibly yellow dots that track down exactly when and where documents, any document, is printed," the Errata researchers wrote.

"Because the NSA logs all printing jobs on its printers, it can use this to match up precisely who printed the document."

dot interpretation

Reports say that the document was printed out six times and that the NSA zeroed in on Winner because she had been in touch with The Intercept.

Errata posted a method of revealing the yellow dot pattern on the document and, using a tool developed by the Electronic Frontier Foundation, found that Winner had printed the document on a printer with model number 54, serial number 29535218. The document was printed on 9 May 2017 at 6:20.

"The NSA almost certainly has a record of who used the printer at that time," Errata said.

The Intercept's Glenn Greenwald, who broke the original Edward Snowden stories, has detailed in his book how he was taught about security measures by the ex-NSA contractor.

However, in this case, it looks like he and the rest of his staff made a bad slip-up which could lead to other potential whistle-blowers being reluctant to trust that their identities would not be compromised by the publication.

Fingers are being pointed at Matt Cole, one of the reporters of the Winner story, as this is the second time that a source in a story he was involved in ended up being prosecuted for espionage. The first was CIA anti-torture whistleblower John Kiriakou.

Graphics: courtesy Errata Security.

Read 3778 times

Please join our community here and become a VIP.

Subscribe to ITWIRE UPDATE Newsletter here
JOIN our iTWireTV our YouTube Community here


The past year has seen a meteoric rise in ransomware incidents worldwide.

Over the past 12 months, SonicWall Capture Labs threat researchers have diligently tracked the meteoric rise in cyberattacks, as well as trends and activity across all threat vectors, including:

Encrypted threats
IoT malware
Zero-day attacks and more

These exclusive findings are now available via the 2022 SonicWall Cyber Threat Report, which ensures SMBs, government agencies, enterprises and other organizations have the actionable threat intelligence needed to combat the rising tide of cybercrime.

Click the button below to get the report.



It's all about Webinars.

Marketing budgets are now focused on Webinars combined with Lead Generation.

If you wish to promote a Webinar we recommend at least a 3 to 4 week campaign prior to your event.

The iTWire campaign will include extensive adverts on our News Site and prominent Newsletter promotion and Promotional News & Editorial. Plus a video interview of the key speaker on iTWire TV which will be used in Promotional Posts on the iTWire Home Page.

Now we are coming out of Lockdown iTWire will be focussed to assisting with your webinars and campaigns and assistance via part payments and extended terms, a Webinar Business Booster Pack and other supportive programs. We can also create your adverts and written content plus coordinate your video interview.

We look forward to discussing your campaign goals with you. Please click the button below.


Sam Varghese

Sam Varghese has been writing for iTWire since 2006, a year after the site came into existence. For nearly a decade thereafter, he wrote mostly about free and open source software, based on his own use of this genre of software. Since May 2016, he has been writing across many areas of technology. He has been a journalist for nearly 40 years in India (Indian Express and Deccan Herald), the UAE (Khaleej Times) and Australia (Daily Commercial News (now defunct) and The Age). His personal blog is titled Irregular Expression.

Share News tips for the iTWire Journalists? Your tip will be anonymous




Guest Opinion

Guest Interviews

Guest Reviews

Guest Research

Guest Research & Case Studies

Channel News