A malicious payload is an attack component responsible for executing an activity to harm the target. Some common examples of malicious payloads are worms, ransomware, and other malware that arrive on computers by clicking bad links or downloading harmful attachments.
Malicious payloads can cause data deletion, encryption, and exfiltration. In some cases, threat actors encrypt payloads to keep their malicious code hidden from antimalware solutions.
Think of malicious payloads as soldiers in camouflage. They only attack when given a signal. Malicious payloads also remain inactive until activated.
Read More about a “Malicious Payload”
In the past, computer worms merely duplicated themselves to slow down an infected system’s performance. Times have changed, as today’s malicious payloads can steal and delete files when executed.
What Harm Can Malicious Payloads Cause?
Malicious payloads can cause several problems that include:
- Data theft: Most cybercriminals steal sensitive data, such as login details and financial information to sell in the Dark Web or use in a data breach. An example would be ZBOT/Zeus, which amassed around 70,000 user accounts in 2009 alone.
- Activity monitoring: Once a malicious payload, such as a spyware, is executed, a hacker can monitor all of a user’s activities. Most hacks are done to collect data on the user to sell to an interested party (e.g., a competitor or an enemy). CoolWebSearch, which exploits Internet Explorer vulnerabilities to hijack a user’s sessions is a notorious spyware.
- File encryption: Ransomware are typically used as malicious payloads to encrypt or change the access to data contained within a target computer. WannaCry, which affected 230,000 computers worldwide is an example of this.
- File deletion: The ExploreZip worm is a malicious payload designed to delete files from an infected Windows computer discovered in 1999.
- Malicious file download: Malicious payloads can also download other malware onto an infected computer to render it unusable. Trojan Downloader is an example of this.
- Unwanted ad display: Once triggered, adware can persistently display pop-up ads. One such malicious payload is DollarRevenue.
- Running unauthorized background processes: Many malicious payloads run silently in the background to spy on its user or slow down a computer’s performance. They are typically backdoors that leave systems under the control of attackers.
How Does a Malicious Payload Work?
Threat actors first need to identify a mode of delivery to the target system. They look for vulnerabilities to exploit. Often, they employ social engineering to trick the user into installing a malware. Once the malicious payload is delivered, it remains hidden until the attacker triggers it. Some execution methods include:
- Double-clicking an installation file: Hackers can send a malicious email attachment that executes the malicious payload when opened.
- Setting up a logic bomb: Another way is to set up behavioral conditions or so-called “logic bombs.” Once the criteria are met, the malicious payload automatically executes.
- Activating a non-executable file: Non-executable files can also trigger malicious payloads. They are often hidden in .png files that are activated when the images are opened.
How Can You Protect against Malicious Payloads?
Because of the wide variety of distribution and execution methods, mitigation also comes in different forms. To protect against malicious payloads, users must:
- Judiciously run a malware scan of all downloaded files even if these come from highly reputable sources.
- Stay abreast of the latest scams and social engineering methods to avoid dealings with potential attackers.
- Use antimalware solutions to screen all incoming communications and downloads.
- Keep software and hardware patched at all times to reduce risks of vulnerability exploitation.
- Discard emails from unknown sources.
- Refrain from clicking links embedded in emails.
Malicious actors often try to limit the sizes of malicious payloads so that these won’t get flagged by security programs and firewalls. That said, cybersecurity officers can limit file attachment and download sizes to prevent attacks that use malicious payloads. Improving employee security awareness also helps.