Which of the following is an umbrella term that describes all forms of malicious software?

Macro Virus: These type of virus infects word, excel, PowerPoint, access and other data files. Once infected repairing of these files is very much difficult.

Master boot record files: MBR viruses are memory-resident viruses and copy itself to the first sector of a storage device which is used for partition tables or OS loading programs .A MBR virus will infect this particular area of Storage device instead of normal files. The easiest way to remove a MBR virus is to clean the MBR area,

Boot sector virus: Boot sector virus infects the boot sector of a HDD or FDD. These are also memory resident in nature. As soon as the computer starts it gets infected from the boot sector.  Cleaning this type of virus is very difficult.

Multipartite virus: A hybrid of Boot and Program/file viruses. They infect program files and when the infected program is executed, these viruses infect the boot record. When you boot the computer next time the virus from the boot record loads in memory and then start infecting other program files on disk

Polymorphic viruses: A virus that can encrypt its code in different ways so that it appears differently in each infection. These viruses are more difficult to detect.

Stealth viruses: These types of viruses use different kind of techniques to avoid detection. They either redirect the disk head to read another sector instead of the one in which they reside or they may alter the reading of the infected file’s size shown in the directory listing. For example, the Whale virus adds 9216 bytes to an infected file; then the virus subtracts the same number of bytes (9216) from the size given in the directory.

Malware terminology

First, is there a standard defining these terms in an unambiguous way?

Malware is a broad term that includes any software which performs malicious actions. There are several common names for various classes of malware. The specific definitions often change over time, as is the case with the term "virus". Common definitions for various forms of malware are:

• Viruses modify existing programs, "infecting" them so their execution also triggers the spread of the virus, until the computer is entirely filled up with maliciously modified software. True viruses are fairly rare now days, but the term continues to be used synonymously with malware.
• Trojans disguise themselves as harmless programs, such as video games or screen savers. They require user interaction to execute. These are common in torrents.
• Worms spread by themselves through the network, often by exploiting software vulnerabilities in networking services. A worm that exploits popular software can spread extremely rapidly. One of the early worms, SQL Slammer, a 376 byte program, infected 75,000 computers within the first 10 minutes. It slowed down the entire internet just as a result of the aggressive replication.
• Rootkits are self-hiding privilege escalation toolkits. They are designed to embed themselves in a system with a high privilege level, ensuring that nothing that runs on the computer can detect it. Rootkits are often able to completely evade antivirus software. Rootkits that infect the boot process to hijack the system early during system start are often called bootkits.
• Ransomware is old, but has gained popularity recently. Simple ransomware simply locks the victim's computer until a ransom is paid. More modern and sophisticated ransomware actually encrypts files and refuses to decrypt until a ransom is paid. These programs often make little effort to avoid removal, as their job is done as soon as they execute for the first time.
• Spyware is any class of malicious software that monitors a user's private activities and reports it back to the owner of the spyware. It can be used by anyone from stalkers to identity thieves.
• Adware is among the least harmful forms of malware. Adware includes any software that displays or injects advertisements on a computer. It is considered malicious when it is installed without consent, or makes attempts to avoid removal. It is commonly implemented as browser toolbars.

Malware can belong to multiple classes. A program that spreads over the network and embeds itself in the kernel for persistence would be both a worm and a rootkit, for example.

Exploits vs executables

Second, in case malware is the umbrella for all harmful softwares, I am thinking of categorizing it into a dichotomy of exploits and executables.

Exploits are not malicious. An exploit is anything that attempts to utilize a security vulnerability to violate the confidentiality, integrity, or availability of a service or task. Sophisticated malware, especially worms, may contain exploits to break security barriers to spread. However, all malware would fall under the classification of executables, as they are all software (or at least executable code, as in the case of shellcode which is not an executable file by itself, but rather is injected into a running process).

What you appear to be describing is the difference between a worm or browser exploit (able to spread with no or little interaction), and a trojan (requires user interaction to trigger infection). This taxonomy doesn't add anything to the existing situation. Improving the terminology is not particularly necessary, as these terms tend to be casual descriptions of generally malicious behavior.

What are the 4 types of attacks in a software?

Is cyber security an umbrella term?

What are the 4 main types of malware?

What do you mean by malicious software?