XMRig: Cryptomining Malware that Works Even Without Web Browser 

The cryptocurrency market may have lost nearly 70% of its market cap from the all-time high of $835 billion in December 2017, but this hasn’t stopped malicious individuals from getting ready for the next cryptocurrency bullrun by spreading cryptocurrency mining malware into the wild.

In the past few months, Coinhive, a cryptocurrency malware that works on web browsers, has wrecked havoc on victims’ computers. But another cryptocurrency malware called “XMRig” is starting to make ripples, entering Check Point’s March 2018 top ten most wanted malwareindex in the 8^thplace for the first time after a 70% increase in global impact.

Coinhive, ranked number one in Check Point’s March 2018 top ten most wanted malware, is a malware that utilizes scripts in taking over some of the processing power on the computers of website visitors without their permission to mine the cryptocurrency Monero.

Cryptocurrency mining is a process of verifying a transaction and a means by which a new coin is released. In order for the transactions to be verified and coins to be released, computational powers of computers are used.

In an ideal world, owners of computers used for cryptocurrency mining should give their consent and should be compensated. Malicious actors bypass this consent aspect and reap all the financial gains for themselves.

What is XMRig?

The original XMRig is an open source code used to mine the cryptocurrency Monero on computers using Windows operating system. The XMRig open source code is in itself not malicious. There are currently 3 software available to mine Monero but XMRig it seems is a choice among malicious actors. 

There’s a demand for Monero as this cryptocurrency boasts of easier mining and untraceable transactions. As of April 20, 2018 (10:30 am GMT+7) one Monero coin is worth $245.

Malicious actors, however, use the XMRig code to conduct illicit mining of Monero cryptocurrency by hijacking the computational power of the infected computers. 

XMRig, used as a cryptocurrency malware, was first seen in the wild in May 2017. As of January 2018, Palo Alto Networksestimated that XMRig victimized nearly 15 million people worldwide. The actual number of victims, Palo Alto Networks said, could be much higher.

In September 2017,security researchers Peter Kálnai and Michal Poslušnýreported that crooks made over $63,000 worth of Monero by modifying legitimate open source Monero mining software XMRig.

According to Kálnai and Poslušný, the malicious actors didn’t apply any changes to the XMRig codebase apart from adding a new wallet address, new mining pool URL and commands to “kill all previously running instances of itself so as not to compete with its new instance” – a process that takes more than just a couple of minutes.

It’s not unusual for malicious actors to reuse codes. Attackers often don’t reinvent the wheel if they don’t have to.

Means of Propagation

Unlike CoinHive, the XMRig cryptocurrency malware doesn’t need a web browser in order to hijack the computational power of the infected computers to mine the cryptocurrency Monero.

Here are 2 methods used by malicious actors to hijack computational power of the infected computers to conduct illicit mining of Monero:

1. Exploiting Known Vulnerability in Microsoft IIS 6.0

According to Kálnai and Poslušný, one of the means by which malicious actors propagate XMRig malware is by exploiting CVE-2017-7269, a known vulnerability in Microsoft IIS 6.0 within Windows Server 2003. By exploiting the vulnerability in Microsoft IIS 6.0, an unauthenticated, remote attacker can execute arbitrary code.

The code to exploit this vulnerability is publicly available. Microsoft hasn’t confirmed this particular security vulnerability and neither has it issued a software update for this vulnerability. Technically though, Windows Server 2003 has reached the end of life (EOL) and as such Microsoft no longer issues software updates.

2. Malvertising Campaign

Adf.ly is an advertising service that pays users when their URLs are clicked. According to Palo Alto Networks, victims were presented with these Adfly advertising URLs, clicked on the provided link, were redirected and found themselves downloading the XMRig cryptocurrency malware onto their computers.

Server Operating System (OS) Attacks

Servers are particularly attractive to attackers as these machines have more computing power, run 24/7 and connect to reliable power source. The reality is that many organizations still use outdated server OS like Windows Server 2003. These outdated server OS are susceptible to repeated exploitation and infection like the XMRig cryptocurrency malware. Cryptocurrency malware like XMRig can result in the slow performance of the servers, shorten the lifespan of these machines and more electricity consumption.

“Cryptomining malware has been quite the success story for cybercriminals, and XMRig’s rise indicates that they are actively invested in modifying and improving their methods in order to stay ahead of the curve,” Maya Horowitz, Threat Intelligence Group Manager at Check Point, said in a statement. “Besides slowing down PCs and servers, cryptomining malware can spread laterally once inside the network, posing a major security threat to its victims. It is therefore critical that enterprises employ a multi-layered cybersecurity strategy that protects against both established malware families and brand new threats.”

How to Prevent XMRig Cryptocurrency Malware Attacks

Here are some of the ways to prevent XMRig cryptocurrency malware attacks:

1. Use Up-to-Date Software, Server OS 

In the case of Windows Server 2003, as the vendor, Microsoft in this case, has stopped issuing security updates, attackers then have a free pass on attacking this system, for instance, attacking a known vulnerability in Microsoft IIS 6.0 within Windows Server 2003.

It’s therefore important to keep your organization’s OS server and all other software up-to-date.

2. Use Ad Blocker

Another way to prevent XMRig cryptocurrency malware is to use an ad blocker. With an ad blocker, you and your staff won’t anymore be susceptible to malvertising link that once clicked, redirects and downloads the XMRig cryptocurrency malware onto computers. An ad block blocks pop-ups, banners, video ads and other intrusive advertising, as well as malware.

Critical Security Flaw Meltdown and Spectre Explained

Meltdown and Spectre are critical security vulnerabilities that affect most modern computer processors and operating systems. These vulnerabilities allow computer programs to steal sensitive data processed on the computer.

Meltdown’s official name is CVE-2017-5754. Spectre is the collective name for 2 vulnerabilities, CVE-2017-5753 and CVE-2017-5715. CVE stands for common vulnerabilities and exposures. It’s a system that provides official references for publicly known cybersecurity vulnerabilities.

A typical computer program isn’t allowed to read data from other computer programs. What Meltdown and Spectre do is access the data stored in the memory of other running computer programs. Data that could be accessed by these vulnerabilities include photos, instant messages, emails and passwords stored in a browser or password manager.

What is Meltdown?

What Meltdown does is break the barrier that isolates computer programs and the operating system. By breaking this barrier, a Meltdown attack could access the operating system and other programs.

Meltdown was independently discovered by security researchers from Google Project Zero, Cyberus Technology and Graz University of Technology.

According to the security researchers who discovered Meltdown, this vulnerability potentially affects every Intel processor which implements “out-of-order execution” meaning, every Intel processor produced since 1995, except Intel Itanium and Intel Atom before 2013. Meltdown has also been shown to potentially affect other processors including ARM and AMD.

Cloud providers which use Intel CPUs and Xen PV and cloud providers without real hardware virtualization may also be potentially affected.

What is Spectre?

What Spectre does is break the barrier that isolates different computer programs. It also tricks a computer program that follows security practices into leaking data.

Spectre was independently discovered by Jann Horn of Google Project Zero and

Paul Kocher.

According to the security researchers who discovered Spectre, almost every modern desktops, laptops, mobile devices and cloud servers are potentially vulnerable. In particular, Intel, AMD and ARM processors are known to be potentially vulnerable to Spectre.

Similarities Between Meltdown and Spectre

Here are the similarities between Meltdown and Spectre:

• Both affect most modern computer chips and operating systems.
• Both could steal sensitive data processed on the computer.
• Both are difficult to detect.

It’s difficult to detect these vulnerabilities as they don’t leave any traces in traditional log files. They’re also difficult to detect as antivirus, for instance, find it hard to distinguish an error-free computer program from Meltdown or Spectre.

Difference Between Meltdown and Spectre

The difference between Meltdown and Spectre is that while Meltdown cracks the barrier that prevents programs from accessing the computer memory, Spectre tricks other computer programs into accessing arbitrary locations in their memory.

Researchers who discovered Meltdown and Spectre said they don’t know whether these vulnerabilities have been exploited into the wild. ProjectZero team at Googlepublicly disclosed these vulnerabilities on January 3, 2018. The team reported these security issues to Intel, AMD and ARM on June 1, 2017.

Intel’s January 2018 press statementstates that the company will issue security updates for at least 90% of Intel CPUs introduced in the last 5 years by January 15, 2018, while security updates for the remaining CPUs will be available by the end of January.

In Intel’s latest press statement, the company said it won’t issue security updates for Spectre for the following processors: Bloomfield line, Clarksfield, Gulftown, Harpertown line, Jasper Forest, Penryn/QC, SoFIA 3GR, Wolfdale line and Yorkfield Line.

Here’s Intel’s explanation why it won't issue security updates of the above-mentioned chips:

“After a comprehensive investigation of the microarchitectures and microcode capabilities for these products, Intel has determined to not release

microcode updates for these products for one or more reasons including, but not limited to the following:

• Micro-architectural characteristics that preclude a practical implementation of features mitigating Variant 2 (CVE-2017-5715)
• Limited Commercially Available System Software support
• Based on customer inputs, most of these products are implemented as ‘closed systems’ and therefore are expected to have a lower likelihood of exposure to these vulnerabilities.”

Most of the above-mentioned unsupported Intel processors are more than 5 years old, some even are more than a decade old, with exception of SoFIA 3GR which was released only in 2015.

According to Microsoft, it has released several security updates to mitigate the effects of Meltdown and Spectre. The company added that it took action to protect its cloud services against these vulnerabilities. “Microsoft has released several updates to help mitigate these vulnerabilities,” Microsoft said in a statement. “We have also taken action to secure our cloud services."

How to Protect Your Organization’s Computers from Meltdown and Spectre

Here are some of the preventive measures to protect your organization’s computers from these vulnerabilities:

• Install security updates.

Meltdown and Spectre affect a number of computer processors, not just Intel. These vulnerabilities also affect operating systems, not just Windows. According to Microsoft, users of Windows operating systems should apply the January and February 2018 Windows security updates as well as the monthly Windows security updates.

• For Windows server operating system, Microsoft recommends making necessary configuration changes to enable protection.

• Avoid unrecognized hyperlinks and websites.

• Avoid downloading files or applications from unknown sources.

• Follow secure password protocols.

• Use security software to help protect against malicious software (malware).

• Consider CPU Options

According to Carnegie Mellon University Software Engineering Institute, there have been reports that the overall CPU performance is impacted by many of the available patches for these vulnerabilities. 

“While we recognize that replacing existing CPUs in already deployed systems is not practical, organizations acquiring new systems should evaluate their CPU selection in light of the expected longevity of this vulnerability in available hardware as well as the performance impacts resulting from the various platform-specific software patches,” Carnegie Mellon University Software Engineering Institute said.