Which type of malware uses files to gain an initial entry into the target machine by exploiting executables, Flash, Java, and documents?

• A. File-based malware
• B. Legitimate applications
• C. Memory code injection
• D. Native applications

Answer: (A)

File-based malware delivers its payload through files, using them as the entry vehicle to gain a foothold on the target system. It exploits weaknesses in common file types and their processing environments—executables like .exe and .dll, as well as documents with macros (Word, Excel), PDFs, or plugins such as Flash or Java—to execute code when the user opens or processes the file. This is how an attacker achieves initial access: tricking the user or exploiting a vulnerability in the file’s handling to run malicious code. Once that initial entry is made, the malware can install, persist, and carry out further actions.

Legitimate applications aren’t malicious, so they wouldn’t be described as a delivery method for malware. Memory code injection refers to techniques used after initial access to run code in memory, not to the initial delivery via files. Native applications is too broad and doesn’t specify the file-based delivery vector.