Just as cancer has 7 warning signs which (if you’ve forgotten) are listed below, malware infection has 7 warning signs as well. If you have any to add, feel free to do so!

1. Popup Ads appear even when no browser is open.

2. Browser navigation gets redirected and/or home page is changed.

3. A security program you never installed pops up “warning” messages.

4. Posts you never wrote appear on social media sites with trolling messages and a link to click.

5. A program holds your computer ransom with a “police” or “FBI” message of a “fine” to pay.

6. You suddenly can’t use your computer’s tools, task manager, Run or regedit (for example).

7. Everything looks normal. Some malware disguises its presence (for example) while it’s sending info back to its “harvester”. Which is why periodic scans with other antivirals (net based) is a good thing to do.

Oh yes… here are those cancer warning signs:

C - Change in bowel or bladder habits.

A - A sore that does not heal.

U - Unusual bleeding or discharge.

T - Thickening or lump in the breast, testicles, or elsewhere.

I - Indigestion or difficulty swallowing.

O – Obvious change in the size, color, shape, or thickness of a wart, mole, or mouth sore.

N - Nagging cough or hoarseness.

The following symptoms may also signal the presence of some types of cancer:

• Persistent headaches.
• Unexplained loss of weight or loss of appetite.
• Chronic pain in bones or any other areas of the body.
• Persistent fatigue, nausea, or vomiting.
• Persistent low-grade fever, either constant or intermittent.
• Repeated infection.

Source: 

http://www.pcmag.com/article2/0,2817,2416788,00.asp

http://www.cancer.org/cancer/index