News broke out that a malicious hacking tools have been used in attacks that were targeted specifically at high-value computers belonging to individuals and organizations of the financial sector in Ukraine. The malware discovered in those attacks is the same malware which ESET researchers managed to discover at the H2 of 2016 belonging to a new hacking group, known as TeleBots. At the moment it is not well known whether or not these hackers simply used the code of the malware developed by the BlackEnergy group or if they are the group themselves, just under a different name.
How The Attacks Are Conducted
The typical phishing e-mail attacks were used when it came down to those attacks. They were also related to Microsoft Excel documents which were attached to those e-mails. To make the users open those e-mails, the attackers perform social engineering (lying) in the e-mails that make them believe the e-mail sent to them is from an organization or a person they are familiar with. As soon as the victim opens the malicious attachment, he or she may see a document with concealed information that prompts to “Enable Content”, like the picture below displays:
As soon as this content is enabled, the user may activate a malicious macro that may cause the infection.
Researchers at ESET have analyzed those malicious macros and have identified that it injects a malicious process that is named “explorer.exe”. This process is executed, and it has been identified to be a trojan that downloads anything the attacker tells it to. More to it, researchers have also identified the malware to be written in the Rust language.
A Python-coded Backdoor Is Downloaded
As soon as an infection related to this downloader is conducted, a backdoor is downloaded, known as the TeleBot Backdoor. This virus uses obfuscation to infect and keep communication with the crooks to receive their “orders”. To communicate with the hackers after an infection has been caused, TeleBot uses advanced techniques to send and receive commands. One of those techniques is Telegram Messenger via which the attackers can input commands based on which the Trojan corresponds.
One of the features of the malware is that it can steal passwords. It contains a module which can be used to collect any saved passwords on the infected device. One of the tools, CredRaptor can attack web browsers, like Chrome, Firefox, Opera and others.
Another module, named plainpwd could be used by the TeleBot team to perform dumps from the system memory. These dumps may contain critical Windows credentials information.
There is also the usually used keylogger to obtain different passwords via collecting information from the typed keystrokes of the victim.
But this is not all. The hackers may also use network sniffers to collect different passwords from the hacked computer as well. Those tools, when viewed separately are nothing significant if you know how to protect yourself, but used in combination can surely steal a great deal of information.
Another information-stealing tool, called LDAP query tool by Eset researchers is reported to collect and send information about the computers that are an infection in a hidden domain; that is specifically made for the victim.
The KillDisk Feature
This feature is the most dangerous one in the TeleBots malware. Similar to ransomware viruses, like GoldenEye it attacks the master boot record and it also overwrites some specific files that allow it to create new files with the same name of the files it attacks. This feature allows it to destroy whole operating systems and delete information on computers, making the computers themselves no longer useful.
The Bottom Line
As a conclusion, whether they are TeleBots or black energy group, the crooks behind this malware have put a lot of effort to defend it from researchers and to even make the above picture of “fsociety” from Mr. Robot display in code.