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Why shouldn’t you scan QR codes?

Quick scanning of QR codes has become very common these days. QR codes are everywhere – on advertisements, products, menus, business cards etc. While they provide a quick and easy way to access information, there are also potential risks associated with scanning random QR codes. This article will discuss the security risks involved and why you should not scan QR codes indiscriminately.

What are QR Codes?

QR codes (short for Quick Response codes) are two-dimensional barcodes that can store information such as website URLs, text, contact details etc. To access this information, you need a smartphone camera and a QR code scanning app. When you scan a QR code using such an app, it converts the black and white pattern into meaningful data. The app then performs the encoded action such as opening a website or dialing a phone number.

How do QR Codes work?

A QR code consists of black squares arranged in a square grid on a white background. The information encoded can be numeric, alphanumeric, or binary. When a QR code is scanned, the black squares are converted into 0s and the white squares into 1s. This binary code is then decoded into data using Reed-Solomon error correction algorithm.

QR Code Structure

Component Description
Finder Patterns Located at three corners help identify the position, size and angle of the QR Code
Alignment Patterns Help correct distortion and determine coordinates of data dots
Timing Patterns Alternating black and white dots, helps count the number of cells and detect distortion
Version Information Indicates the QR code version based on pattern complexity
Format Information Contains error correction level and data mask pattern information
Data and Error Correction Codewords Encoded data and Reed-Solomon error correction codewords
Quiet Zone Empty margin around code helps scanner detect edges of code

These components allow the QR code to be scanned from any angle and even if partly damaged.

QR Code Scanning Risks

While QR codes provide a lot of convenience, they also pose security risks if scanned blindly without verifying the source. Some of the ways scanning an unknown QR code can compromise your security include:

Phishing Attacks

One of the biggest risks of scanning random QR codes is that they may direct you to a phishing website. This fraudulent site mimics a legitimate website to steal your personal information like login credentials or credit card details. The URL may look authentic but it is controlled by scammers.

Malware Download

Some QR codes are designed to automatically download malware on your device when scanned. This malware can then infect your device, steal data, encrypt files for ransom, spy on your activities or even take complete control of the device.

Unsafe WiFi Access

Public QR codes may connect your device to free but unsafe public WiFi networks controlled by cybercriminals. Connecting to such networks makes you an easy target for hacking attacks.

Financial Fraud

Fraudsters can create fake QR codes to collect payment or donation for illegal purposes. Scanning such codes would give them direct access to your financial accounts linked to the payment app.

Tracking and Profiling

Some QR codes are used to collect data about the scanner for tracking or profiling purposes without taking consent. The data gathered can include your location, device details, browsing habits etc.

Risk Impact
Phishing Attack Account compromise, identity theft, financial fraud
Malware Download Data and identity theft, device hijacking, ransom demands
Unsafe WiFi Access Man-in-the-middle attacks, data interception
Financial Fraud Unauthorized payments and transactions
Tracking and Profiling Privacy violation, targeted scamming

How to Scan QR Codes Safely

While QR code risks are real, you can take certain precautions to scan them safely:

Verify Source

Only scan QR codes shared from trusted sources or in trusted environments like reputed stores and restaurants. Avoid scanning randomly stuck or posted QR codes.

Use a QR Scanner with Safety Features

Download a reliable QR code scanner app that provides safety features like real-time malicious URL detection. These can alert you of potential threats before opening a website.

Don’t Scan Login QR Codes

Avoid scanning QR codes that take you directly to a login page. Instead, type the URL directly and login from there to avoid phishing.

Check the URL

Once scanned, check if the URL looks legitimate and matches the expected source before proceeding.

Use a VPN

Using a VPN encrypts your web traffic and hides your IP address and location, providing an extra layer of protection.

Limit Permissions

Only allow the QR scanner minimum permissions required like camera access. Disallow access to contacts, storage etc.

Install Antivirus Software

Having reputed antivirus software installed helps detect and block malicious sites or downloaded files.

Avoid Scanning Multiple Times

Refrain from repeatedly scanning the same QR code. It may send you to a different destination than the first time.

Examples of Malicious QR Codes

Some real-life examples of malicious QR code scams:

Free Cryptocurrency

Fraudsters posted QR codes promising free Bitcoin or other cryptocurrency if scanned. Victims were taken to phishing sites and tricked into entering their crypto wallet credentials.

Free Gift Cards

QR codes offering free gift cards from brands like Amazon and Starbucks circulated online. Scanning them led users to fake giveaway sites that stole personal data or planted malware.

Rogue Access Points

A cybercriminal placed QR codes offering free WiFi access in cafes and airports to distribute the access details of a rogue access point they controlled, allowing them to spy on connected users.

Parking Meter Scam

Bogus QR codes were placed on top of parking meters to redirect payments to a scammer instead of the municipal administration. Victims ended up with parking fines.

Best Practices for Businesses Using QR Codes

For businesses using QR codes, some best practices include:

Place Visibly

Position QR codes in expected and visible locations like tables at restaurants, product packaging or Signages to build trust.

Use Organizational Branding

Customize QR codes using your business’s colors, logo and standard placement. This establishes authenticity.

Direct to Official Site

Link the QR code to your official website or app instead of external sites to prevent redirection.

Secureshorten Links

If linking externally, use a URL shortener that provides analytics and prevents redirection, like Bitly.

Include a Call to Action

Mention what action is expected after scanning clearly near the QR code like “Scan for menu” to avoid confusion.

Monitor Usage and Analytics

Use QR management software to track scans and redirects to identify suspicious activity or sources.

Change Frequently

Rotate and update QR codes periodically to prevent continued abuse if compromised initially.


QR codes provide a quick and convenient way to access digital information but also carry risks like phishing, malware and fraud if scanned blindly. Always verify the source, check the destination URL and use a trusted QR scanner app to stay secure. For businesses, customize and secure codes, track analytics and change periodically to prevent misuse. With adequate precautions, QR codes can be safely leveraged for their benefits while avoiding becoming attack vectors for cybercriminals.