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:
- Iranian hacker group deploys malicious Snake game to target Egyptian and Israeli critical infrastructure
December 3, 2025
An Iranian-aligned hacking group tracked as ‘MuddyWater’ has dramatically shifted tactics in attacks against Israeli and Egyptian critical infrastructure. Previous campaigns by the group, observed by ESET Research, were characteristically noisy in their tactics, techniques, and procedures (TTPs) making them easily detectable. However, the group has begun employing a new backdoor deployed via the Fooder loader, ...
- Fintech firm Marquis alerts dozens of US banks and credit unions of a data breach after ransomware attack
December 3, 2025
Fintech company Marquis is notifying dozens of U.S. banks and credit unions that they had customer data stolen in a cyberattack earlier this year. Details of the cyberattack emerged this week after Marquis filed data breach notices with several U.S. states confirming its August 14 incident as a ransomware attack. Texas-based Marquis is a marketing and compliance ...
- Attackers have a new way to slip past your MFA
December 3, 2025
Attackers are using a tool called Evilginx to steal session cookies, letting them bypass the need for a multi-factor authentication (MFA) token. Researchers are warning about a rise in cases where this method is used against educational institutions. Evilginx is an attacker-in-the-middle phishing toolkit that sits between you and the real website, relaying the genuine sign-in ...
- A data breach at analytics giant Mixpanel leaves a lot of open questions
December 2, 2025
A cybersecurity incident at analytics provider Mixpanel announced just hours before the U.S. Thanksgiving holiday weekend could set a new standard for how not to announce a data breach. To recap: In a bare bones blog post last Wednesday, Mixpanel chief executive Jen Taylor announced that the company had detected an unspecified security incident on November ...
- Unraveling Water Saci’s New Multi-Format, AI-Enhanced Attacks Propagated via WhatsApp
December 2, 2025
Brazil has seen a recent surge of threats delivered via WhatsApp. As observed in Trend Micro previously published research on the SORVEPOTEL malware and the broader Water Saci campaignopen on a new tab, this popular platform has been used to launch sophisticated campaigns. Unsuspecting users receive convincing messages from trusted contacts, often crafted to exploit social ...
- Google patches 107 Android flaws, including two being actively exploited
December 2, 2025
Google has patched 107 vulnerabilities in Android in its December 2025 Android Security Bulletin, including two high-severity flaws that are being actively exploited. The December updates are available for Android 13, 14, 15, and 16. Android vendors are notified of all issues at least a month before publication, but that doesn’t always mean the patches ...