Threat actors are impersonating the United States Post Office (USPS) in a legitimate-looking malvertising campaign that diverts victims to a phishing site to steal payment-card and banking credentials, researchers have found.
A malicious ad appears on Google searches for both mobile and desktop users looking to track packages via the USPS website, Jérôme Segura, director of threat intelligence at Malwarebytes Labs revealed in a blog post published July 5.
Though it looks "completely trustworthy," it isn't, he said. Instead, it redirects victims to a malicious site that first collects their address and credit card details, and then requires them to log into their bank account for verification, eventually stealing that info as well.
Segura cites Jesse Baumgartner, marketing director at Overt Operator, as the person who first discovered the campaign. Baumgartner shared screenshots of his experience attempting to track a package that led him onto a scam website in a LinkedIn post.
Malwarebytes Labs researchers set out to find the scam themselves and were immediately able to find the authentic-looking ad by performing a simple Google search for "usp tracking."
"Incredibly, the ad snippet contains the official website and logo of the United States Postal Service and yet, the 'advertiser' whose verified legal name is Анастасія Іващенко (Ukraine), has nothing to do with it," Segura wrote.
Malwarebytes Labs has reported the campaign to Google and for its part, Cloudflare has already flagged the domains as phishing sites.
The campaign is yet another reminder that no matter how much awareness there is about malicious ads, links, and websites lurking on the Internet, threat actors still successfully wield oft-used tactics that abuse and impersonate trusted entities to trick and defraud Internet users, he said.
"Malvertising via search results remains an issue that affects both consumers and businesses who place their trust behind well-known brands," Segura wrote in the post.
A recent malvertising campaign in January also leveraged trusted brands by targeting users searching for Bitwarden and 1Password's Web vaults on Google. Threat actors used paid ads with links to cleverly spoofed sites for stealing credentials to the unsuspecting users' password vaults.
Creating a Convincing Phishing Campaign
Segura broke down how the actor or actors behind the USPS campaign managed to make it look so convincing to an end user. Essentially, they used tactics that can apply to various types of malvertising, he said.
There are two ad campaigns — one that targets mobile users, and the other targeting desktop users. While the ads appear to use the official USPS URL while redirecting victims to an attacker-controlled domain, the URLs shown in the ad "are pure visual artifacts that have nothing to do with what you actually click on," Segura explained.
"When you click on the ad, the first URL returned is Google's own which contains various metrics related to the ad, followed by the advertiser's own URL," he said. "Users never get to see this, and that is what makes malvertising via brand impersonation so dangerous."
Victims that click on the ad land on a website that asks them to enter their package tracking number, just as any page for this type of request would. However, upon submitting that information they receive an error informing them that their package couldn't be delivered "due to incomplete information in delivery address."
This might arouse suspicion, but likely not, as it's pretty typical for someone tracking a package to receive this type of notification, Segura noted. However, the next step of the attack — in which users are then asked to enter their full address again as well as submit their credit-card data to pay a small fee of 35 cents — should raise a red flag, he said.
It's at this point where victims enter the phishing site and attackers can steal their data, making the small fee "completely irrelevant," since giving up payment-card data — which can be used by the threat actor or resold on criminal markets — can result in much more damage to someone, Segura observed.
The final step of the attack is a request that victims enter credentials for their financial institution through a dynamic page that generates a template based on the credit-card info provided. For instance, if a person submits data for a Visa card associated with JP Morgan Bank, the page will ask the target to login to the JP Morgan page. Other banks and cards will result in different templates specific to the data provided, Segura said, similar to how banking Trojan overlays work.
Recommendations to Thwart Malvertising
As mentioned, malvertising is already a well-known method used by cybercriminals to steal user credentials. However, while awareness is key to avoid falling victim to a campaign, "training can only go so far" because of how legitimate modern malicious scams created by attackers look, Segura wrote.
One way to stop these campaigns before they reach end users is for search engines to apply stricter controls to combat the brand impersonation that threat actors have adopted so successfully, he said.
"When it comes to software downloads, one solution that comes to mind is reserving a placeholder for the official download page and never allowing an ad to take this spot, Segura wrote, noting that Microsoft's Bing already has applied policy with success.
Applying real-time browser protection that can disrupt the malvertising kill chain from the initial ad all the way to the payload — whether it be malware, phishing, or another type of scam — also can prevent and mitigate this type of attack.