Attackers typically try to pass off malware as legitimate applications or as potentially unwanted programs that users deliberately search for and download, such as cheats or cracks. They often rely on ad and affiliate networks to deliver their creations to victims’ devices. This post examines a less conventional case: a well-known backdoor distributed under the guise of adware. The attackers may have chosen this distribution method because the adware was signed by the developer. On top of that, users often manually add these apps to exclusions, so their useful features don’t get blocked.
Some time ago, a client asked us to analyze a file with the MD5 hash c24e99f9437feacaa63766a3cde3fe3d and add it to our detection database. We initially classified it as adware, but a cursory analysis turned up suspicious network activity, which prompted us to dig deeper. It turned out the sample did far more than serve ads. In fact, its advertising functionality doesn’t even work; instead, it triggers an infection chain that delivers the ValleyRAT backdoor.
Read more…
Source: Kaspersky
Sign up for the Cyber Security Review Newsletter
The latest cyber security news and insights delivered right to your inbox
Related:
- Nemty Ransomware – Learning by Doing
April 2, 2020
The McAfee Advanced Threat Research Team (ATR) observed a new ransomware family named ‘Nemty’ on 20 August 2019. We are in an era where ransomware developers face multiple struggles, from the great work done by the security community to protect against their malware, to initiatives such as the No More Ransom project that offer some victims a way ...
- Loncom packer: from backdoors to Cobalt Strike
April 2, 2020
The previous story described an unusual way of distributing malware under disguise of an update for an expired security certificate. After the story went out, we conducted a detailed analysis of the samples we had obtained, with some interesting findings. All of the malware we examined from the campaign was packed with the same packer, which we ...
- Wiper Malware Called “Coronavirus” Spreads Among Windows Victims
April 1, 2020
A new Windows malware has emerged that makes disks unusable by overwriting the master boot record (MBR). It takes its cue from the COVID-19 pandemic, calling itself simply “Coronavirus.” Overwriting the MBR is the same trick that the infamous NotPetya wiper malware used in 2017 in a campaign that caused widespread, global financial damage. Worryingly, according to the ...
- LimeRAT malware is being spread through VelvetSweatshop Excel encryption technique
April 1, 2020
A new campaign is spreading the LimeRAT Remote Access Trojan by harnessing an old encryption technique in Excel files. LimeRAT is a simple Trojan designed for Windows machines. The malware is able to install backdoors on infected machines and encrypt files in the same way as typical ransomware strains, add PCs to botnets, and install cryptocurrency ...
- Holy water: ongoing targeted water-holing attack in Asia
March 31, 2020
On December 4, 2019, we discovered watering hole websites that were compromised to selectively trigger a drive-by download attack with fake Adobe Flash update warnings. This campaign has been active since at least May 2019, and targets an Asian religious and ethnic group. The threat actor’s unsophisticated but creative toolset has been evolving a lot since ...
- SilverTerrier: 2019 Nigerian Business Email Compromise Update
March 31, 2020
In 2019, Business Email Compromise (BEC) maintained its rankings as both the most profitable and the most prominent threat facing our customers. According to the Federal Bureau of Investigation (FBI) Internet Crime Complaint Center (IC3), which recently released its annual report, US$1.77 billion in losses were attributed to BEC attacks over the course of 2019. This number ...