Cyber crimes: hacking, eavesdropping, phishing, ransomware
- Hacking: gaining unauthorised access to a computer or network to steal, change or destroy data. Ethical (white-hat) hackers find weaknesses with permission to fix them; black-hat hackers do it with bad intent.
- Eavesdropping: secretly listening to or reading private communication, for example on unsecured public Wi-Fi.
- Phishing: fake emails, SMS (smishing), calls (vishing) or websites that look genuine and trick you into revealing passwords, OTPs or card numbers. Signs: urgency, spelling errors, odd sender addresses, links that don't match.
- Ransomware: malware that locks or encrypts your files and demands payment (ransom) to unlock them. Regular backups are the best defence.
Cyber trolls and cyberbullying
A cyber troll posts insulting or provoking comments to upset people and start fights. Cyberbullying is using digital platforms to harass, threaten, shame or exclude someone repeatedly: mean messages, sharing embarrassing photos, fake profiles, or rumours.
What to do: don't reply; keep screenshots; block and report the account; tell a parent or teacher; in India, report at cybercrime.gov.in or call 1930. Never bully back.
Malware: virus, worm, trojan, spyware, adware
Malware (malicious software) is software made to harm a device or steal data.
- Virus: attaches itself to a file or program and spreads when that file is run or shared; can delete or damage data.
- Worm: spreads by itself across networks without needing a host file.
- Trojan horse: pretends to be useful (a free game or cracked app) but secretly opens a back door for attackers. It does not copy itself.
- Spyware: secretly records what you do (keys typed, sites visited).
- Adware: shows unwanted pop-up ads, slows the device and may track you.
Protection: antivirus, updates, downloads only from official stores, no pirated software.
Safe browsing
- Use websites with https:// and a padlock, especially for payments.
- Keep the browser, OS and apps updated.
- Use antivirus and keep the firewall on.
- Don't click unknown links, pop-ups or 'You won a prize' ads; don't download from untrusted sites.
- Avoid logging in or paying on public Wi-Fi.
- Clear cookies and history on shared computers; use private browsing there.
Identity protection
Identity theft is when someone steals your personal details (name, Aadhaar, passwords, bank data) to pretend to be you. Protect yourself:
- Use strong, unique passwords: 12+ characters mixing upper and lower case, numbers and symbols; a password manager helps.
- Turn on two-factor authentication (2FA/OTP); never share OTPs, PINs or CVV with anyone.
- Share personal information only on trusted sites; don't post ID cards, tickets or boarding passes online.
- Log out after using shared or public computers.
- Check bank messages and report anything strange quickly.
Key formulas and definitions
- Cyber crime: hacking, eavesdropping, phishing, ransomware, trolling, bullying
- Virus = spreads via files; Worm = spreads alone; Trojan = disguised; Adware = pop-up ads
- Safe browsing: https, updates, antivirus, firewall, no unknown links
- Identity: strong unique password + 2FA; never share OTP
- Bullying: Stop, Block, Report, Tell
Worked examples
1. An email says: 'Your account will be closed. Click here and enter your password.' The sender is support@bank-secure-help.xyz. What is it and what should you do?
Phishing (urgent tone, odd address). Don't click; delete or report it; contact the bank through its official app or number.
2. A student downloads a 'free' cracked game. Later his files are locked and a note asks for payment. Name the threats.
The cracked game was a trojan that installed ransomware. Defences: download from official stores and keep backups.
3. Which is stronger: 'riya2008' or 'Mango!River7Sky'? Why?
'Mango!River7Sky': it is longer and mixes upper/lower case, a number and a symbol; 'riya2008' uses a name and birth year that are easy to guess.
4. Someone keeps posting mean comments on a classmate's photos. What is this and how should the classmate respond?
Cyberbullying. Don't reply, take screenshots, block and report the account, and tell a parent or teacher; it can also be reported at cybercrime.gov.in.
Common mistakes
- Thinking a trojan copies itself like a virus. A trojan hides inside a useful-looking program; it does not self-replicate.
- Sharing an OTP with someone who says they are from the bank. Banks never ask for OTPs.
- Replying angrily to trolls, which gives them what they want.
- Using the same password for every account; one leak then opens all of them.