Number system and computer virus

1234567
Across
  1. 2. is the smallest unit in computer processing.
  2. 4. uses only 16 digits including 6 letters of alphabet.
  3. 5. this virus is
  4. 7. this program keeps your device safe and notify's you when a virus is in any website.
Down
  1. 1. this virus only activates on Friday.
  2. 3. but allows to enter other virus on your device.
  3. 6. this is a base2 number system.