An advanced persistent threat (APT) is a cyberattack in which an intruder infiltrates a network to steal sensitive data over an extended period. APT attacks are carefully planned and designed to evade existing security measures and fly under the radar. Organizations can implement security measures and mitigate the risks posed by advanced persistent threats by recognizing the stages of infiltration, escalation, and exfiltration.
See more: What is an advanced persistent threat (APT)?
The first phase of an APT attack involves gaining unauthorized access to a network. Attackers often employ social engineering techniques, such as spear-phishing emails, to target high-level individuals within an organization. These emails are carefully crafted to appear legitimate, often referencing ongoing projects or coming from trusted team members.
Once inside the network, the attackers expand their access and gather critical information. They may deploy malware to move laterally across the network, mapping its structure and obtaining credentials such as account names and passwords. This enables them to access valuable business data and establish backdoors for future stealth operations.
In the final stage of an APT attack, cybercriminals extract the stolen information from the compromised network without detection. They typically store the data in a secure location within the network until they have collected enough to make the exfiltration worthwhile. To distract security teams and tie up network resources, attackers may launch denial-of-service (DoS) attacks or other diversionary tactics.
APT attacks differ from traditional cyberattacks in their sophistication and persistence. They often leave behind unique signs that organizations should watch for:
To defend against APT attacks, organizations must adopt a multi-layered approach to cybersecurity. Here are some effective tactics to employ:
Deploy capabilities that provide comprehensive visibility across the network to avoid blind spots that could serve as havens for cyber threats.
Leverage indicators of compromise (IOCs) to enrich security information and event management (SIEM) systems. This helps in event correlation and detection of potential threats.
Collaborate with a reputable cybersecurity firm to access expertise and assistance in responding to sophisticated cyber threats.
Employ a WAF to filter, monitor, and analyze web traffic at the application level, protecting against malicious HTTP and HTTPS requests.
Utilize threat intelligence to profile threat actors, track campaigns, and identify emerging malware families. Contextual understanding of attacks is crucial for effective defense.
Consider 24/7 managed threat-hunting services to complement existing cybersecurity measures. Human-based threat hunting can provide valuable insights and uncover hidden threats.
Go deeper: How to manage persistent threats and zero-day vulnerabilities
Several notable APT groups have been identified and tracked by cybersecurity firms. These groups, often associated with nation-states or organized cybercriminal entities, employ advanced techniques in their attacks. Here are some examples:
Assessed to be acting on behalf of the Russian Foreign Intelligence Service, Cozy Bear targets political, scientific, and national security entities through spear-phishing campaigns and the distribution of various malware types.
This Vietnam-based adversary has been active since at least 2012. They utilize a wide range of tactics, such as strategic web compromise (SWC) operations and spear-phishing emails, to distribute malware and infiltrate targeted organizations.
Operating out of China, Wicked Panda is known for its sophisticated and prolific cyber activities. It consists of several groups working in the interests of the Chinese state while carrying out criminal activities for profit.
Secure email solutions can mitigate the threat of spear-phishing attacks. Employing encryption, authentication, and other security measures helps protect sensitive information and prevent unauthorized access. Integrating secure email practices into an organization's cybersecurity strategy is necessary for safeguarding against APT attacks.
In May 2024, Kaspersky discovered a new APT group called CloudSorcerer targeting Russian government agencies. The group uses cloud services like Microsoft Graph, Yandex Cloud, and Dropbox for controlling their attacks and stealing data. Their malware uses advanced techniques to hide its activities and adapt based on the system it’s running on.
The malware starts by dropping a hidden file on the victim’s computer, which then connects to cloud services to receive instructions. It can adjust its behavior depending on the software it's running with, making it harder to detect. CloudSorcerer also uses GitHub for initial communications and sometimes tries to get information from Russian photo-sharing sites.
In a related development, Proofpoint found a similar attack, named UNK_ArbitraryAcrobat, targeting a U.S. organization. This attack used phishing emails to trick people into downloading a malicious file, which then used similar techniques to those of CloudSorcerer.
An advanced persistent threat (APT) attack is a sophisticated, long-term cyberattack in which an unauthorized individual gains access to a network and remains undetected for an extended period. In healthcare, APT attacks can target sensitive patient data, medical records, and healthcare infrastructure, posing risks to the confidentiality, integrity, and availability of protected health information (PHI).
APT attacks are a threat because they are designed to stealthily infiltrate and maintain a presence within healthcare networks, allowing attackers to continuously harvest sensitive data and disrupt operations. The advanced techniques and persistence of these attacks make them difficult to detect and mitigate, increasing the risk of substantial data breaches, financial losses, and compromised patient care.
Read also: HIPAA Compliant Email: The Definitive Guide