A new phishing campaign employing bogus shipping delivery lures installs the STRRAT remote access trojan on the computers of unsuspecting victims. Fortinet identified the new campaign after detecting phishing emails mimicking Maersk Shipping, a worldwide shipping behemoth, but utilising seemingly authentic email addresses.
STRRAT is a multi-functional Remote Access Trojan that dates to at least mid-2020. It is unusually Java-based and is normally sent to victims via phishing email. Previous STRAAT operations, like other phishing attacks, used an intermediary dropper (e.g., a malicious Excel macro) attached to the email that downloaded the ultimate payload when viewed. Instead of using that method, this sample attaches the final payload directly to the phishing email.
In the case of Maersk Shipping, the message eventually goes through "acalpulps[.]com" before being delivered to the final recipient after leaving the sender's local infrastructure. This domain was only registered in August 2021, which makes it questionable. Furthermore, the domain utilised in the "Reply-To" address, "ftqplc[.]in," was recently registered (October 2021), making it highly suspicious as well. The email body urges the recipient to open attachments regarding a pending shipment.
A PNG image and two Zip archives are directly attached to the sample email. "maersk.png" is simply an image file. However, the two Zip archives “SHIPMENT_DOCUMENTS_INV-PLIST01256_BL PDF[.]zip” and “SHIPMENT_DOCUMENTS_INV-PLIST01256_BL PDF (2)[.]zip” include an embedded copy of STRRAT. When one of these archives is unzipped, the file “SHIPMENT_DOCUMENTS_INV-PLIST01256_BL PDF[.]jar” is displayed. However, when you open the file in Jar Explorer, a few things become clear.
Firstly, this package contains a significant number of Java class files. Second, the strings in the class "FirstRun" appear to be scrambled or encoded. Lines beginning with "ALLATORIxDEMO" denote the presence of the Allatori Java Obfuscator.
STRRAT malware first collects basic information about the host system, such as its architecture and any anti-virus software that are operating on it, before checking local storage and network capability. STRRAT can collect user keystrokes, enable remote control operation, steal passwords from web browsers such as Chrome, Firefox, and Microsoft Edge, steal passwords from email clients such as Outlook, Thunderbird, and Foxmail, and launch a pseudo-ransomware module to simulate an infection.
Trojans like STRRAT are frequently overlooked because they are less sophisticated and more randomly distributed. However, this phishing attempt proves that even little threats can cause significant damage to organizations.
