What Is Persistence in Cybersecurity?
Persistence has become the weapon of choice for today’s cunning threat actors. As hackers continue to refine their skills, they have become masters of stealth—silently infiltrating their target environment, biding their time until their ultimate objective is achieved.
In the world of cybersecurity, attackers have a sneaky trick up their sleeves called persistence. It’s like a secret agent that allows them to silently sneak into systems and stay hidden, even when things get shaken up. They’re like ghosts, maintaining long-term access to your precious data, regardless of restarts or changed credentials. It’s a game of cat and mouse, and only the savviest defenders can spot their crafty moves. Watch out for those sneaky bad actors who can slip in an implant or a “stub” that not only outsmarts antivirus programs, but also unleashes a whole new wave of malware mischief! Unleashing its stealthy wrath, this devious malware cunningly disguises itself within innocent startup folders and concealed within scheduled tasks and services, making it an elusive foe to uncover.
When the system is rebooted or logged off and on again, the stub or malware is triggered to run again. In other words, persistence allows hackers to maintain access to your environments, often without your knowledge.
How Does Persistence Enable Malware?
Persistence can be utilized to maintain the operation of malware and potentially facilitate the propagation of other malicious software. Persistent malware can be utilized by attackers to retain access to a network while they search for targeted data to steal. In addition, persistent malware may be utilized for various illicit activities, including click fraud or cryptojacking.
Fortunately, through persistence, defenders can identify malware. When defenders identify persistence, they have the ability to remove it, thereby preventing the threat actor from accessing the system and halting the attackers’ progress.
It is important to keep in mind that detecting malware is only a temporary solution to the larger issue of persistence. If defenders do not detect the persistence in the environment, threat actors can easily redistribute the malware. Malware detection only addresses one symptom and does not solve the underlying problem. This is the reason its so imperative to identify and remove persistence.
Is Persistence and Advanced Persistent Threat (APT) the Same Thing?
No. Advanced persistent threats, or APTs, are a form of attack that utilize persistence capabilities. However, not all persistence-enabled attacks are considered advanced persistent threats (APTs).
Advanced Persistent Threats (APTs) are a type of cyberattack that is often carried out by nation-state cybercrime groups. On the other hand, persistence is a broader term that encompasses both advanced attacks and attacks carried out by lower-level threat actors and groups.
The Stuxnet Advanced Persistent Threat
Stuxnet is widely recognized as one of the most prominent examples of an APT. Stuxnet was developed in the early 2000s by the National Security Agency (NSA) of the United States and the cyber division of Israel’s military (Unit 8200). This APT was created with the intention of disrupting Iran’s nuclear program.
This APT was considered innovative during its time. The malware scanned the operating system for Siemens Step 7 software, which is commonly used by industrial computers as PLCs to monitor electro-mechanical equipment. The malware detected the software and then updated its code. This caused the equipment’s instructions for self-damage. At the same time, the malware transmitted incorrect data back to the central controller. This enabled it to go unnoticed, even by the human operators monitoring the equipment, until the equipment started experiencing malfunctions.
In the end, Stuxnet had an impact on over 200,000 computers and caused significant damage to nearly 1,000 centrifuges at Iran’s Natanz nuclear facility.
An in-depth analysis of Persistence-Enabled Attacks
Persistence is usually situated in the middle of the cyber kill chain. Once hackers have gained access to an environment, their objective is to maintain that access undetected.
Below are the five main stages in the cyber kill chain.
What Are Common Malware Persistence Mechanisms?
MITRE ATT&CK®, the ultimate source of knowledge on adversary tactics, has unveiled a jaw-dropping revelation – a whopping 19 distinct malware persistence mechanisms that cunning attackers employ to stealthily infiltrate and dwell undetected in environments. When it comes to hackers, they have a knack for establishing persistence in not just one, but three cunning ways.
1. The execution of auto-start on boot or logon.
This malware persistence mechanism involves a hacker exploiting a legitimate operating system process, such as a system reboot or logon. One method a hacker can use to achieve persistence is by adding an entry to the run keys in Windows Registry or the Startup folder. Consequently, any mentioned programs will be executed upon user login.
2. Boot or Logon Initialization Scripts are used to initialize the system upon startup or user login.
In the case of this persistence technique, hackers commonly utilize local credentials or an administrator account to execute scripts that are automatically activated during boot or logon, thus ensuring continuity. Attackers have the ability to execute additional programs or transmit information to an internal logging server.
You can reduce the likelihood of being affected by this common malware persistence mechanism by properly setting permissions and limiting write access to logon scripts to specific administrators. However, this is not a guaranteed preventive measure.
3. A task or job that has been planned in advance.
This persistence mechanism happens when an attacker exploits the task scheduling feature to initiate or repeat the execution of malicious code.
One method that is commonly used is exploiting Windows Task Scheduler, which allows for the execution of programs during system startup or on a scheduled basis. For instance, TrickBot, a trojan spyware program, has been observed creating scheduled tasks on compromised systems in order to maintain persistence for the attack.
The presence of utilities to schedule programs or scripts in all major operating systems poses a risk to nearly everyone. One way to identify this commonly used malware persistence mechanism is by regularly reviewing your task scheduler to identify any changes to tasks that do not align with known software or patch cycles.
Do security tools have the capability to detect and remove persistence?
Numerous companies in the security industry assert that they can detect and remove persistence using artificial intelligence (AI) and automation. The issue is that persistence is intentionally designed to be discreet and go unnoticed. It frequently achieves this by employing methods of obfuscation or evasion that automated tools are unlikely to detect.
On the contrary, humans possess contextual awareness to detect any discrepancies. Threat hunting utilizes both innovative technology and human intelligence to detect attacks that automated security tools alone may overlook.
Human threat hunters and innovative technology work together effectively to detect and remove persistent threats.