PE file

Definition

A PE (Portable Executable) file is a file format used in Windows operating systems for executables, object code, and dynamic-link libraries (DLLs). It serves as the standard file format for executable files in Windows and contains crucial information that the operating system needs to manage the executable code. Understanding PE files is essential for static malware analysis as they often provide insights into the structure and behavior of potentially malicious software.

5 Must Know Facts For Your Next Test

1. PE files contain several important headers, including the DOS header, PE header, and section headers, which define how the executable should be loaded into memory.
2. The sections of a PE file include code (.text), data (.data), and resources (.rsrc), which store executable code, global variables, and icons or images respectively.
3. PE files can also include an import table that lists external functions from DLLs that the executable will call, which is crucial for understanding its dependencies.
4. Malware authors often manipulate PE file structures to hide malicious code or evade detection, making understanding this format essential in malware analysis.
5. Tools like PE Explorer and CFF Explorer are commonly used in static malware analysis to dissect and analyze the contents of PE files.

Review Questions

• How do the various headers within a PE file contribute to static malware analysis?
  • The headers within a PE file, such as the DOS header and PE header, provide essential metadata about how the executable should be loaded and executed. By analyzing these headers during static malware analysis, investigators can identify key characteristics of the executable, including entry points and dependencies on other modules. This information helps in understanding the potential behavior of the program without executing it, thus identifying malicious intent.
• Discuss how an import table within a PE file can be indicative of potential malware behavior.
  • The import table in a PE file lists external functions that the executable relies on from DLLs. By examining this table, analysts can identify suspicious or unusual function calls that may indicate malicious activity, such as API calls related to network communication or system manipulation. If the imported functions align with known behaviors of malware, this can serve as a strong indicator of the file's potential threat level.
• Evaluate the significance of understanding the structure of PE files in developing effective antivirus strategies.
  • Understanding the structure of PE files is crucial for developing effective antivirus strategies because it allows security professionals to identify and analyze malicious code embedded within these files. By knowing what typical PE file structures look like, antivirus tools can detect anomalies or modifications that indicate tampering by malware authors. This knowledge also aids in creating signatures for known threats, improving proactive measures against new variants by recognizing patterns in how malware typically manipulates PE files.

Related terms

Executable: A type of computer file that contains a program capable of being executed or run as a process on a computer.

Static Analysis: The examination of code without executing it, allowing analysts to understand program behavior and identify vulnerabilities or malicious elements.

DLL (Dynamic-Link Library): A type of file that contains code and data that can be used by multiple programs at the same time, allowing for modular programming and efficient memory usage.