CMS based sites such as WordPress and Joomla are the popular targets for cybercriminals, they hijack those sites and inject malicious contents.
ThreatLabZ researchers detected a campaign that targets WordPress and Joomla sites to distribute Shade/Troldesh ransomware, backdoors, redirectors, and a variety of phishing pages.
Hackers use to hijack several hundreds of CMS sites and inject the Troldesh ransomware and phishing pages. All the compromised websites using WordPress versions between 4.8.9 to 5.1.1 and they SSL issued through Automatic Certificate Management Environment such as Let’s Encrypt, Cpanel and others.
According to zscaler, among the compromised sites, 13.6 percent contains Shade ransomware, 27.6 percent contains phishing pages and rest of the sites contains coinminers, adware, and malicious redirectors.
Attackers favoring the .well-know hidden directory for storing and distributing ransomware. The hidden .well-know directory is created by the site administratory to verify the ownership of the domain.
Shade Ransomware Infection
Shade ransomware infected sites contain HTML, ZIP, and EXE (.jpg) files, the HTML files are to redirect the users in downloading the zip file, the zip file contains highly obfuscated that downloads payload to Temp location.
The downloaded payload is the Shade/Troldesh ransomware that encrypts all the users file with AES-256 and appends a filename(.ID_of_infected_machine.crypted000007).
“It drops README1.txt to README10.txt on the desktop and changes the wallpaper as shown below”, reads ZScaller blog post.
Phishing pages also stored in the hidden directories to hide them from website administrators and to increase in the life of the phishing page in the compromised site.
The phishing pages are related to Office 365, Microsoft, DHL, Dropbox, Bank of America, Yahoo, Gmail, and others.