A week in security (March 12 – March 18)

Last week on Malwarebytes Labs, we took a look at the inner workings of a fileless attack, explored what happened in a zero day ransomware attack aimed at South Koreans, gave you hints and tips for avoiding cold calls, and took a deep dive into the secretive world of GrayKey. Other news The Equifax story just keep rumbling on. (Source: The Guardian) Some Meltdown and Spectre updates. (Source: The … [Read more...]

Hancitor: fileless attack with a kernel trick

This article was authored by David Sánchez, Mickaël Roger, and Jérôme Segura During the past few years, malicious spam campaigns have proven to be one of the most efficient infection vectors, in part due to a combination of social engineering and a regular number of Office vulnerabilities. The interesting aspect about social engineering is that it capitalizes on the user’s poor decision to execute … [Read more...]

Encryption 101: How to break encryption

Continuing on in our Encryption 101 series, where we gave a malware analyst’s primer on encryption and demonstrated encryption techniques using ShiOne ransomware, we now look at what it takes to break an encryption. In order for something as powerful as encryption to break, there needs to be some kind of secret flaw. That flaw is often a result of an error in implementation. There are a … [Read more...]

Blast from the past: stowaway Virut delivered with Chinese DDoS bot

Recently, we described an unusual Chinese drive-by attack that was delivering a variant of the Avzhan DDoS bot. The attack also contained multiple components that were not-so-new. Among the exploits, the newest was from 2016. Avzhan is also not a recent malware—the compilation timestamp of the unpacked payload was from August 2015. But there was one more unusual thing that triggered our attention. … [Read more...]

Encryption 101: ShiOne ransomware case study

In part one of this series, Encryption 101: a malware analyst’s primer, we introduced some of the basic encryption concepts used in malware. If you haven’t read it, we suggest going back for a review, as it’s necessary in order to be able to fully follow part two, our case study. In this study, we will be reviewing the encryption of the ransomware ShiOne line by line. The main … [Read more...]

The state of malicious cryptomining

While cryptocurrencies have been around for a long time and used for legitimate purposes, online criminals have certainly tarnished their reputation. Unfortunately, the same benefits offered by these decentralized and somewhat anonymous digital currencies were quickly abused to extort money, as was the case during the various ransomware outbreaks we’ve witnessed in the last few years. As the value … [Read more...]

Avzhan DDoS bot dropped by Chinese drive-by attack

The Avzhan DDoS bot has been known since 2010, but recently we saw it in wild again, being dropped by a Chinese drive-by attack. In this post, we’ll take a deep dive into its functionality and compare the sample we captured with the one described in the past. Analyzed sample 05749f08ebd9762511c6da92481e87d8 – The main sample, dropped by the exploit … [Read more...]

Kotlin-based malicious apps penetrate Google market

An open-source programming language, Kotlin is a fully-supported official programming language for Android. Google boasts that Kotlin contains safety features in order to make apps “healthy by default.” Many apps are already built with Kotlin, from the hottest startups to Fortune 500 companies. (Twitter, Uber, Pinterest) Concise while being expressive, Kotlin reduces the amount of … [Read more...]

Ransomware’s difficult second album

The last year has seen all manner of cybercrime, from scams and social engineering to malvertising and malspam. What’s interesting is that so many “next-gen,” sophisticated malware mainstays like exploits have dropped in popularity, while other more traditional types such as spyware have shot up dramatically —to the tune of an 882 percent increase in UK detections. Meanwhile, … [Read more...]

Scarab ransomware: new variant changes tactics

The Scarab ransomware was discovered in June 2017. Since then, several variants have been created and discovered in the wild. The most popular or widespread versions were distributed via the Necurs botnet and initially written in Visual C compiled. However, after unpacking, we’ve found that another variant discovered in December 2017, called Scarabey, is distributed a little differently, … [Read more...]