An Inside Look at Chinese Hackers’ Night Sky Ransomware

A hacking collective in China is distributing Night Sky ransomware through Log4j exploits.  Microsoft has been closely analyzing the crypto-locking malware to identify its source point, characteristics, and potential lines of defense.
 

How was Night Sky Identified?

MalwareHunterTeam, a respected digital security research group, discovered Night Sky.  The digital security specialists at MalwareHunterTeam identified the new form of ransomware on January 1.
 

Where Have the Attacks Occurred?

Night Sky has targeted victims in Japan and Bangladesh.  However, the attack is likely to spread to other countries in the days and weeks ahead.  
 

How is the Night Sky Attack Launched?

Digital miscreants exploit weak points in Apache Log4j software to transmit the Night Sky ransomware.  The attacks started in January. The hackers are zeroing in on susceptibilities within web-facing systems to deploy the ransomware.  

Microsoft representatives have stated they are observing several digital attackers implementing exploits of the vulnerabilities within current malware strategies and kits.  The attacks range from those of the hands-on-keyboard variety to coin miners.  Perhaps the worst aspect of this unique attack is target organizations might not even know their environment is being attacked.

The rise of the ransomware digital thieves targeting weaknesses within Log4j comes on the heels of Apache’s initial public alert on the 10th of December.  Apache highlighted a vulnerability within the Java Naming and Directory Interface API, specifically stating that the Log4j logging utility ahead of 2.15.0 has the potential for exploitation.  Such exploitation allows for subsequent control of the target system.
 

How Many Log4Shell Vulnerabilities are There?

All in all, three Log4Shell vulnerabilities exist. The CVE-2021-45046 vulnerability is transmitted through an insufficient repair for the JNDI weakness. The CVE-2021-4104 vulnerability can be exploited with certain Log4j 1.x uses. The CVE-2021-44228 vulnerability centers on the JNDI issue within Log4j2.x.
 

Why is Night Sky a Problem?
 

Night Sky is transmitted when digital thieves exploit flaws in Log4j through unpatched VMware Horizon versions.  The ransomware appears to be a completely new variation.  The attack is particularly challenging to avoid as the DEV-0401 group relies on altered domain names that appear valid yet have slight misspellings.  
 

The Night Sky hackers are performing double extortion.  This means the Night Sky ransomware specialists insist on payment for the decryptor of locked corporate information and to ensure the data is not stolen.  Stolen data has the potential to be sold on the black market.  It is interesting to note that one Night Sky victim received a ransomware payment request of $800,000.  
 

What is the Best Line of Defense?

Vendors are now tasked with pinpointing and patching susceptible software and systems.  Updates are available to the general computing community.  Computer users are encouraged to download these updates and perform tests to ensure they work.