Saturday, November 26, 2016

RIP Tom Hanks? No, it's a fake malware scam

Tom Hanks is not dead. That doesn't stop crooks from using news of his demise to attract victims.

Updated 29 November with additional context after I analyzed the malicious link. TL;DR: Tom Hanks is not dead, and the fake news link on Facebook leads to a malicious website. As an aside, Tom Hanks is not the first celebrity to be used in fake news scams, and I am sure he won't be the last. Other recent malvertisements have claimed the demise of Harrison Ford, Sylvester Stallone, Beyonce, and even Facebook's own CEO Mark Zuckerberg.


No, Tom Hanks is not dead. However, a malicious advertisement circulating on Facebook over Thanksgiving weekend uses that headline as bait; readers that click the "news story" to find out more instead get more than they bargained for. 


Instead of a news article, the advertisement leads to a web page that blares an incessant alarm sound and displays the following warning message. As a clever twist, the malicious content itself imitates Google's own malicious website warning. 

Victims that call the phone number on the screen will no doubt be instructed to pay a "Microsoft Technical Support" fee to have the malware removed - a twist on the classic technical support scam.


This scam presents an imitation of the Google Deceptive Website warning screen.

The red screen above will look familiar to many readers: Google's Chrome browser, along with Mozilla Firefox and Apple Safari, are part of the Google Safe Browsing project. These browsers display a warning such as the one below before opening a website Google has determined to be malicious or deceptive. 

However, the real Google Safe Browsing warning does not include wailing sirens and incessant popup messages. Nor does it claim you have already been infected and direct you to call a technical support number for assistance. The purpose of Safe Browsing is to warn you before you open a dangerous web site:

The actual Google Safe Browsing screen does not claim that you are already infected

As the US Federal Trade Commission describes, technical support scams are a common method crooks use to separate you from your money. The classic approach is, you run a "free antivirus check" website, which informs you that you are infected by all sorts of nastiness. A more recent variation is, you get a phone call from someone pretending to be "Microsoft Technical Support," claiming again that your PC is infected. In both cases, the crooks' goal is to trick you into giving them remote access or paying for "cleaning" that you don’t need.

In this case, the scam appears to be purely social engineering, and not a technical exploit. The page does not actually download any malware to the PC. Instead, it uses a JavaScript loop to keep the warning message on screen if a reader tries to cancel the warning, and another JavaScript routine to keep the reader from closing the browser window.

This scam relies on JavaScript in the browser to repeatedly warn the user of a fake infection

The following message is displayed atop the red warning screen, and refreshes every second if you try to close it. This technique is particularly annoying because it interrupts any other browser windows to make you acknowledge the alert... which of course returns almost immediately once you acknowledge it.

The popup screen used by this scam directs the victim to call a fake Microsoft Technical Support center.



What can you do?

  • If you have encountered this, or any other website displaying a popup alert that your PC is infected, use the Escape key to close the popup warning - and immediately press CTRL-F4 to close the browser tab before the popup returns.
     
  • This scam relies on JavaScript, a feature of modern browsers that enables interactive websites, but that also can be abused to enable terrible browsing experiences. Disabling JavaScript will thwart this scam, though may break other websites. Here is how to disable JavaScript.
     
  • Replace the domain name service provided by your ISP with a malware-blocking DNS such as OpenDNS - it's easy and extremely effective. DNS is how your computer translates "website.com" into a computer-understandable address. If you try to go to a known-malicious site, OpenDNS simply changes the address and sends you to a page saying "you don't really want to go there."

    Full disclosure: this only works after a site has been deemed malicious; if you are among the first to visit a new malicious site, OpenDNS doesn't yet know it is malicious and so won't stop you. Still, it is a very strong addition to your home or business network security.

Do you have something to add? A question you'd like answered? Think I'm out of my mind? Join the conversation below, reach out by email at david (at) securityforrealpeople.com, or hit me up on Twitter at @dnlongen

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Whois David?

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I have spent the better part of two decades in information technology and security, with roots in application developer support, system administration, and network security. My specialty is cyber threat intelligence - software vulnerabilities and patching, malware, social networking risks, etc. In particular, I strive to write about complex cyber topics in a way that can be understood by those outside the infosec industry.

Why do I do this? A common comment I get from friends and family is that complex security topics give them headaches. They want to know in simple terms how to stay safe in a connected world. Folks like me and my peers have chosen to make a profession out of hacking and defending. I've been doing this for the better part of two decades, and so have a high degree of knowledge in the field. Others have chosen different paths - paths where I would be lost. This is my effort to share my knowledge with those that are experts in something else.

When not in front of a digital screen, I spend my time raising five rambunctious teens and pre-teens - including two sets of twins. Our family enjoys archery, raising show and meat rabbits, and simply enjoying life in the Texas hill country.

For a decade I served as either Commander or a division leader for the Awana Club in Dripping Springs, Texas; while I have retired from that role I continue to have a passion for children's ministry. At the moment I teach 1st through 3rd grade Sunday School. Follow FBC Dripping Springs Kids to see what is going on in our children's ministries.