Emotet is an advanced, modular banking Trojan that primarily functions as a downloader or dropper of other banking Trojans. Emotet continues to be among the most costly and destructive malware affecting state, local, tribal, and territorial (SLTT) governments, and the private and public sectors.
Emotet is an advanced, modular banking Trojan that primarily functions as a downloader or dropper of other banking Trojans. Additionally, Emotet is a polymorphic banking Trojan that can evade typical signature-based detection. It has several methods for maintaining persistence, including auto-start registry keys and services. It uses modular Dynamic Link Libraries (DLLs) to continuously evolve and update its capabilities. Furthermore, Emotet is Virtual Machine-aware and can generate false indicators if run in a virtual environment.
The U.S. Department of Homeland Security published an alert on Emotet in July 2018, describing it as “an advanced, modular banking Trojan that primarily functions as a downloader or dropper of other banking Trojans,” and warning that it’s very difficult to combat, capable of evading typical signature-based detection, and determined to spread itself. The alert explains that “Emotet infections have cost SLTT (state, local, tribal, and territorial) governments up to $1 million per incident to remediate.”
Emotet infections typically start with a simple phishing email that contains an attachment or a link to download a file. The recipient is persuaded to click the link or open the file and they unwittingly set in motion a macro that downloads a malicious payload. As soon as the device is infected, Emotet starts trying to spread to other devices on the network. Once Trojan. Emotet has infected a networked machine, it will propagate by enumerating network resources and write to share drives, as well as brute force user accounts. Infected machines attempt to spread Emotet laterally via brute-forcing of domain credentials, as well as externally via its built-in spam module. As a result, the Emotet botnet is quite active and responsible for much of the malspam we encounter. The Trojan may download the following modules to carry out various tasks:
- Banking module
- Distributed denial of service (DDoS) module
- Spam module
- Email client info stealer module
- Browser info stealer module
- Personal Storage Table (PST) info stealer module
Impact
Negative consequences of Emotet infection include
- temporary or permanent loss of sensitive or proprietary information,
- disruption to regular operations,
- financial losses incurred to restore systems and files, and
- potential harm to an organization’s reputation.
Prevention techniques
-
Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
- Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
- Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
- Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
- Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
- Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
For more Cybersecurity information contact us at help@theweborion.com