Oyster Backdoor: How Trojanized Popular Software Downloads are Spreading it

Malvertising Campaign Targets Popular Software with Trojanized Installers

A recent report by Rapid7 has uncovered a new malvertising campaign that is using trojanized installers for well-known software like Google Chrome and Microsoft Teams. According to the findings, the campaign is delivering a backdoor called Oyster, also known as Broomstick and CleanUpLoader.

Sophisticated Tactics by Malvertisers

The malicious actors behind the campaign have set up lookalike websites that host the malicious payloads. When users search for these popular software titles on search engines like Google and Bing, they are redirected to these fake websites, unknowingly downloading the trojanized installers.

The Danger of Backdoors like Oyster

Once the trojanized installer is downloaded and executed, the Oyster backdoor is deployed onto the victim’s system. Backdoors like Oyster are particularly dangerous as they provide remote access to the attacker, allowing them to carry out various malicious activities without the user’s knowledge.

Mitigating the Threat of Malvertising Campaigns

To protect against such malvertising campaigns, users are advised to exercise caution when downloading software from the internet. It is essential to only download applications from official sources and avoid clicking on suspicious links or advertisements, especially when searching for popular software titles.

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Implementing Security Measures

Furthermore, organizations can bolster their defenses against malvertising campaigns by implementing robust security measures such as endpoint protection, web filtering, and user education. Regular security awareness training can help employees recognize potential threats and avoid falling victim to malicious schemes.

Security Solution Recommendations

Security solutions like antivirus software, intrusion detection systems, and endpoint firewalls can also help detect and prevent the installation of trojanized software and backdoors. By having layered security defenses in place, organizations can mitigate the risk of falling prey to sophisticated malvertising campaigns.


In conclusion, the malvertising campaign leveraging trojanized installers for popular software highlights the importance of staying vigilant and adopting proactive security measures. By being cautious of suspicious download sources and implementing robust security solutions, both individuals and organizations can reduce the risk of falling victim to such cyber threats. Remember, when it comes to IT security, it’s always better to be safe than sorry.

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