Malicious URLs overtake email attachments as the biggest malware threat

There's been a sharp rise in the number of phishing and URL-based attacks over the last year, with malicious URLs now being used four-times as often as attachments in email threats.

Malicious links are embedded in messages, buttons, and even within attachments like PDFs or Word documents to entice clicks that initiate credential phishing or malware downloads.

According to a new report from Proofpoint, researchers observed around 3.7 billion URL-based threats over a six month period, highlighting the growing scale of the problem.

Only 8.3 million of these threats were intended to deliver malware, however, with the most frequently-observed payloads in URL-based campaigns being remote monitoring and management (RMM) tools and remote access software (RAS).

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These attacks are getting increasingly difficult for users to identify, Proofpoint noted, with cyber criminals now using advanced social engineering techniques and AI-generated content to create their malicious URLs.

Not only are they impersonating trusted brands, but also abusing legitimate services, tricking users with fake error prompts and bypassing traditional security by embedding threats in QR codes and SMS messages.

"URL-based phishing threats are no longer confined to the inbox, they can be carried out anywhere and are often extremely difficult for people to identify,” said Selena Larson, senior threat intelligence analyst at Proofpoint.

New techniques are paying off for hackers

Some of the URL-based credential phishing campaigns with the highest volumes in the past 12 months have been facilitated by off-the-shelf 'phish kits' like CoGUI and Darcula.

CoGUI is primarily used by Chinese-speaking threat actors, according to Proofpoint. These high-volume campaigns typically include message counts ranging from the hundreds of thousands to tens of millions at a time, and are mainly used to steal personal details such as credit card numbers.

Meanwhile, ClickFix malware campaigns - a phishing technique that lures users into running malicious code by displaying fake error messages or CAPTCHA screens - are up by nearly 400% year-over-year.

Malware operators are exploiting the urge to resolve a perceived technical issue, helping them spread remote access trojans (RATs), infostealers and loaders.

QR code and smishing threats are rising

Proofpoint also identified more than 4.2 million QR code phishing threats in the first half of 2025 alone. In these cases, the main aim of attackers is credential phishing, with 3.7 billion URL-based attacks aimed at stealing logins.

With phishing lures that impersonate trusted brands and use off-the-shelf tools such as CoGUI and Darcula phish kits, Proofpoint said even low-skilled actors can deploy highly convincing campaigns that bypass multi-factor authentication (MFA) and lead to full account takeover.

The number of smishing campaigns rocketed by 2,534%, as attackers shift their focus to mobile devices - at least 55% of suspected SMS-based phishing messages analyzed by the firm contained malicious URLs, often mimicking government communications or delivery services.

“From QR codes in emails and fake CAPTCHA pages to mobile-first smishing scams, attackers are weaponizing trusted platforms and familiar experiences to exploit human psychology," said Larson.

"Defending against these threats requires multi-layered, AI-powered detection and a human-centric security strategy.”

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