Description

Chinese-linked threat actors known as Silver Fox have been observed targeting Indian organizations through carefully crafted phishing operations that mimic official income tax communications. These campaigns rely on highly convincing emails that appear to originate from the Income Tax Department, prompting recipients to open attachments or links related to tax matters. By abusing the trust placed in government correspondence, attackers increase the likelihood of user interaction and initial compromise. The infection chain begins with a deceptive PDF attachment branded with an Indian company’s name. Opening the document redirects the victim to a malicious website that delivers an executable disguised as a tax-related file. This file functions as a loader, initiating multiple hidden malware stages that work together to evade detection while securing long-term access. The approach highlights how attackers combine social engineering with familiar file formats to bypass conventional security controls. Researchers from CloudSEK later uncovered that the campaign had been incorrectly attributed to other threat groups in earlier analyses. Their investigation clarified Silver Fox’s involvement, emphasizing the importance of precise attribution in cybersecurity. Correctly identifying the adversary allows organizations to design defenses aligned with the attacker’s known techniques rather than relying on ineffective or misdirected protections. Technically, the attack abuses DLL hijacking by using a legitimate signed executable, Thunder.exe, alongside a malicious DLL. This technique allows attacker code to run unnoticed while performing anti-analysis checks, disabling system updates, and decrypting payloads directly in memory. The final stage deploys Valley RAT, a powerful remote access tool with resilient command-and-control mechanisms, capable of surveillance, data theft, and modular expansion, posing a serious risk to Indian enterprises.