GreyNoise has observed a significant surge in login scanning activity targeting Palo Alto Networks PAN-OS GlobalProtect portals. Over the last 30 days, nearly 24,000 unique IP addresses have attempted to access these portals. The pattern suggests a coordinated effort to probe network defenses and identify exposed or vulnerable systems, potentially as a precursor to targeted exploitation.
Recent patterns observed by GreyNoise suggest that this activity may signal the emergence of new vulnerabilities in the near future:
“Over the past 18 to 24 months, we’ve observed a consistent pattern of deliberate targeting of older vulnerabilities or well-worn attack and reconnaissance attempts against specific technologies,” said Bob Rudis, VP of Data Science at GreyNoise. “These patterns often coincide with new vulnerabilities emerging 2 to 4 weeks later.”
On March 29, right before Easter weekend, we received notifications about something unusual happening with the open-source project XZ Utils, which provides lossless data compression on virtually all Unix-like operating systems, including Linux.
The initial warning was sent to the Open Source Security mailing list sent by Andres Freund, who discovered that XZ Utils versions 5.6.0 and 5.6.1 are impacted by a backdoor. A few hours later, the US government’s CISA and OpenSSF warned about a critical problem: an installed XZ backdoored version could lead to unauthorized remote access.