There is often confusion between heuristic analysis and what’s commonly known as a “heuristic virus”. Heuristics are more accurately described as heuristic analysis, the method in which dangerous code is found. The term, heuristic virus, can often be misleading.

While the term heuristic virus can be referred to as the method in which malicious code is detected, it’s better suited to describe the specific virus, Heur.Invader—a malware designed to change system settings.

Heuristic analysis is an adaptive antivirus defense that discovers malicious code through educated guesses. The need for manual review lowers the scalability of this type of analysis, as the techniques are less accurate. Enter machine learning in antivirus software. By automating the majority of processes, and manually analyzing for continuous improvement within the remainder, antivirus software is more effective with zero risks of file-based malware infection.

Heuristics: Detection Approach or Virus?

Heuristics are generally used in antivirus software alongside scanning solutions as a way to estimate where malicious code is on your computer. What may be referred to as a “heuristic virus” is the detection of possible malware, adware, trojans, or other threats. This preliminary warning may appear in a scan as “HEUR” and should be considered suspect code to further inspect.


Heuristic analysis can detect potential viruses without needing to specifically identify them. The process is agile and continually improves as it discovers threats. The longer it runs, the more efficient and effective it becomes. Unfortunately, heuristic analysis is labor-intensive and often results in false positives that must be manually reviewed.

What Is Heuristic Analysis?

Heuristic analysis is based on several techniques. These techniques explore file source codes and match them with previously discovered threats. Depending on the proportion of the match, the system will find the probability of a threat and flag code that’s likely malicious.

Heuristic-based analysis uses a number of techniques to analyze behaviors and threat levels including:

  • Dynamic scanning: Analyzes the behavior of a file in a simulated environment.
  • File analysis: Analyzes the intent, destination, and purpose of a file.
  • Multicriteria analysis (MCA): Analyzes the weight of the potential threat.

Heuristic virus scans use these analysis techniques for virus detection within code.

Heuristic Virus Detection

Signature-based detection and sandboxing are used with heuristic virus detection for the most effective result.


Heuristic-based detection may determine code is a threat if the program:

  • Persists in the memory after performing its task.
  • Attempts to write to the disk.
  • Modifies required operating system files.
  • Mimics known malware.

Heuristic Scanning

Adjusting the sensitivity level within heuristic scans determines the tolerance level of suspicious files. With an increased level of sensitivity, there is a greater level of protection, but also a higher risk of false positives.

Enable the heuristic scan and choose its sensitivity levels with the following steps:

  1. Open the settings in the main window of the program.
  2. Configure the scan properties in the scan section.
  3. Select the checkbox to enable the scan in the Heuristic section.
  4. To alter the sensitivity level, open settings and select one of the three levels.

How Do You Get Rid of a Heuristic Virus?

A remote server controls the Heur.Invader virus. When removing the Heur.Invader virus, use antivirus software to run a full scan in safe mode. Remove the threat from your machine once detected.


This critical threat can disable antivirus software, install malicious programs, collect sensitive information, and change security settings. When removing the Heur.Invader virus, always boot the computer in safe mode. Doing so starts the computer only with the necessary drivers and services and won’t load the virus—which can disable antivirus software.

  1. Boot the computer in safe mode.
  2. Run your full antivirus software scan as normal.
  3. Once the scan denotes malicious code, inspect the element manually for false positives.
  4. Remove the malicious code.

In sum, heuristic analysis finds inconsistencies in an application and can be found in most antivirus software programs. The downside of heuristic detection, though, is the need for manual review due to frequent false positives. Pair this detection method with automation and other detection tools for the most accurate outcomes.

Sources: Panda Security 1, 2 | Techwalla | Wikileaks | IET