Cybercriminals abusing legitimate Google Cloud Storage services to host the malicious payload and delivered to compromise the organization networks through bypassing the security controls.
In this case, Attackers targeting Google Cloud Storage service domain storage.googleapis.com which is used by many companies around the world.
This campaign mainly targeting employees of banks and financial services companies which resides in the U.S. and the UK since August.
This attack initially distributed via email campaign that contain attached phishing links pointed to the malicious website which is hosted in Google Cloud Sevices.
Researchers analyzed and found that 4,600 phishing sites that used legit hosting services which
Instead of using malicious attachments, attackers using malicious links in
Identify malicious URLs only if they are already in their threat repositories and it’s a very rare case scenario since the attacker keep change the payload hosted domain.
Infection Process from Google Cloud Storage
Initially, attackers start the malicious campaign through email that contains an embedded URL from compromised email accounts.
Malicious URL’s posed as legitimate URL from Google cloud storage services that used to delivery 2 types of payload to compromise the endpoints: VBS scripts and JAR files
Attackers dropping malicious obfuscated VBS scripts which
the JAR files we identified, we believe one file (Swift invoice.jar) belongs to the Houdini/jRAT malware family.
The other JAR files are still being investigated, and we believe they belong to the Qrat malware family., Researchers said.