Thousands of VNC Servers Open to the Internet Detected
Cyble security researchers have observed an increase in attacks targeting open VNC sessions. VNC graphical desktop sharing system is a program developed to provide users with the convenience of remote control of a computer or system.
Recent studies have found that over 8,000 unauthenticated VNC installations are accessible over the Internet. The number of VNC servers left open to the Internet is mostly concentrated in China, Sweden, and the United States.
It has been noticed that there is a significant increase in attacks on port 5900, the default port of VNC servers accessible over the Internet.
Most of these attacks are carried out in the Netherlands, Russia, and Ukraine. In addition, some VNC servers vulnerable to attacks are owned by organizations serving critical infrastructure industries, including water treatment plants, manufacturers, and research facilities. Therefore, this situation puts critical infrastructure systems such as HMI, SCADA/ICS, and workstations connected via VNC and accessible over the Internet at risk.
Threat actors targeting the security of such systems can interfere with predefined configurations, take industrial control systems (ICS) out of service, disrupt the supply chain and processes in the affected industries, or gain access to sensitive data that can be used to compromise ICS systems. In addition, it has been observed that threat actors use these VNC accesses in their trading activities on platforms on the Deep Web.
Leaving VNCs open to the Internet without authentication makes it very easy for threat actors to break into the vulnerable network and wreak havoc. In this context, it is recommended to consider the following security practices to prevent institutions/organizations using VNC and similar solutions from being the target of possible attacks.
- Ensure that critical systems in the IT environment are behind firewalls,
- Internet exposure of VNCs should be minimized.
- SCADA/ICS systems should be used in the latest versions published by the official vendor,
- Strong password policies should be enforced within the organization,
- Access controls within the organization should be configured correctly,
- Network traffic should be constantly monitored for the security of the institution/organization inventory,
- All necessary security measures for VNC must be enabled,
- Cyber security awareness should be raised for those working in the SCADA/ICS environment.
Zoom Releases Updates Fixing A Critical Vulnerability Affecting macOS
Zoom has released security updates that fix a vulnerability in the macOS operating system that could allow a threat actor to take control of a user’s system. (Reference Link)
The security vulnerability with code CVE-2022-28756 affects the automatic update feature of the application. A low-privileged threat actor can exploit the vulnerability to gain root privileges on the vulnerable operating system during the automatic update process of versions 5.7.3 to 5.11.3. The vulnerability was identified by Patrick Wardle, founder of the Objective-See Foundation, and presented at the annual world-known Def Con Hack conference.
The vulnerability has been fixed in version 5.11.5 of the currently available Zoom app for macOS.
It is recommended that users using vulnerable versions of the Zoom App for macOS immediately apply the updates that fix the vulnerability so that they are not the target of attacks that can be carried out using the vulnerability.
A Critical Security Vulnerability Detected Affecting Cisco ASA and Firepower Solutions
A critical security vulnerability has been detected in the Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) software that could allow an unauthenticated threat actor to gain access to the RSA Private Key. ASA software is the core operating system of Cisco’s ASA security appliances that protect data centers and corporate networks, while FTD software provides next-generation firewall (NGFW) service.
The vulnerability with code CVE-2022-20866 is caused by a logic error caused by storing the RSA key in memory on a hardware platform that performs hardware-based encryption. A remote threat actor can exploit the vulnerability to execute a Lenstra Side-Channel attack and gain access to the RSA key. A compromised RSA Private Key can be used to impersonate a device running Cisco ASA Software or Cisco FTD Software or to decrypt device traffic.
Cisco stated that the vulnerability only affects Cisco ASA Software 9.16.1 and later versions, Cisco FTD Software 7.0.0 and later versions, and has released security updates that fix the vulnerability. In this context, it is recommended that users using vulnerable Cisco ASA and FTD software versions immediately apply the published updates so that they are not the target of attacks that can be carried out using the vulnerability.
A New Attack Campaign Targeted Public Institutions and Industrial Organizations
A new attack campaign targeting defense industry organizations and public institutions in various countries have been detected by Kaspersky ICS CERT researchers. Due to the overlap of techniques, tactics, and procedures (TTPs) used, the attack attributed to the TA428 APT group targets industrial facilities, design bureaus, research institutes, government agencies, and ministries in various Eastern European countries (Belarus, Russia, and Ukraine) as well as Afghanistan.
The attack starts with the distribution of phishing emails created by threat actors using internal data of the targeted organization to the targets. Microsoft Word documents attached to phishing emails contain malicious code that exploits the CVE-2017-11882 vulnerability.
The vulnerability allows threat actors to execute arbitrary code on the vulnerable system through the PortDoor Backdoor malware without user interaction. A new variant of PortDoor Backdoor was detected in this campaign. The latest version PortDoor collects data from the infected system and sends it to command and control (CnC) servers controlled by threat actors. In addition, it was observed that backdoor malware such as nccTrojan, Logtu, Cotx, and DNSep was also used in the attack.
Threat actors, who first gain access to the targeted system, try to distribute malware to other computers in the corporate network in later stages. For this purpose, Ladon malware, which Chinese-origin threat actors frequently use, helps TA428 threat actors to carry out Lateral Movement activities in the target network. The final stage of the attack includes capturing the target organization’s domain controller by threat actors and acquiring critical documents and files from all workstations and servers of the organization.
This attack campaign demonstrates that spear phishing attacks remain one of the critical threats to industrial businesses and public institutions. Therefore, industrial organizations and public institutions must take a proactive cybersecurity stance to prevent such attacks successfully. In this context, it is recommended to consider the following security practices to avoid being the target of this and similar phishing or malware campaigns.
- Emails, attachments, and links from unknown, suspicious parties should not be respected.
- File/program or application downloads should be from legitimate and reliable sources.
- The installed system, program, or applications should be used in the current versions where the vulnerabilities are fixed.
- Comprehensive Anti-Virus/Anti-Malware security solutions should be used.
- Institution/organization personnel should be aware of potential phishing/social engineering attacks.
- IOC findings related to the campaign should be blocked from security solutions.