Over the past year, the social engineering tactics used for cyber attacks have evolved significantly as attackers manipulate the inherent trust, biases, and vulnerabilities of individual human behavior to gain unauthorized access to sensitive information or systems.
Our “year in review” Cloud and Threat Report, revealed that in 2023, social engineering was the most common way attackers gained initial access to organizations. Social engineering-led attacks place an organization’s employees in a crucial role, essentially manipulating them into opening the door for the attacker to walk through. Social engineering can come in the form of disguised links (malicious ones posing as a link to a genuine service or system the user accesses every day, such as OneDrive), downloads suggested by trusted search engines (criminals have sophisticated SEO teams), and lately even deep faked phone calls purporting to be from colleagues asking for help accessing something.
The attraction for attackers in this method of access is that it enables access to inherently secure systems that are normally quickly patched against known security vulnerabilities and that provide limited remote access. Our research identified two of the leading categories of social engineering techniques to target employees—phishing and trojans.
Phishing data in the cloud
Phishing is the tactic of disguising emails and online messages to trick users into clicking on malicious links to steal credentials or other sensitive information. Netskope’s data found that employees fell for phishing scams three times more frequently than downloaded trojans. On average, 29 out of every 10,000 employees clicked on a phishing link every month in 2023, meaning that a company with a 10k headcount had an average of 348 employees clicking on phishing links throughout the year.
Among the cloud apps targeted by adversaries in 2023, Microsoft’s suite stands out above all the rest as the most popular. Attacks through OneDrive, SharePoint via Microsoft Teams and Outlook dominated the list of applications targeted for phishing malware downloads. With their popularity among enterprises, Microsoft app credentials are a lucrative target for attackers, and employees are accustomed to trusting Microsoft app links, clicking on them throughout their working day.
We also saw sites like Amazon, eBay, and gaming platform Steam being highly targeted throughout the year, while websites for government bodies such as the Internal Revenue Service (IRS) were spoofed to steal financial information.
Access to accounts for other nefarious activities is also common. For example Netflix and Facebook were the most popular streaming and social media platforms targeted, where account details gathered from phishing scams can be sold on the dark web. Given the numerous elections in 2024 around the world, Facebook users will need to be vigilant to phishing attempts designed to collect accounts in order to spread misinformation.
Some attackers operate as initial access brokers, selling the stolen credentials, banking information and other data on the black market. This means that what appears a simple phishing attack in the first instance could be the first stage in a more complex attack. There is a sophisticated and entrepreneurial ecosystem of cyber attackers selling this access for use in cybercrime, corporate espionage and ransomware attacks, and the activity of this organized crime will only grow as cloud apps increasingly embed into our daily lives.
Trojans and cloud based SaaS
Trojans are a type of malware often disguised as a legitimate program. Users are tricked into downloading the malicious code which in turn gives the attacker access to a system. Cloud based software-as-a-service (SaaS) applications are particularly attractive as enterprise professionals are accustomed to routinely clicking links for these services over their working day. Netskope found that Trojans are the second most common attack vector, as employees downloaded an average of 11 Trojans per month per 10,000 users, meaning a typical organization of that size would have had an average of 132 Trojans downloaded by users on their network per year.
Like phishing attacks, Microsoft applications featured prominently as the host for Trojan downloads. OneDrive topped the charts while SharePoint, targeted by attackers through Microsoft Teams, was in second place.
SaaS apps that provide free file hosting services are particularly attractive to cost-conscious attackers. This includes cloud storage apps (Microsoft OneDrive, Google Drive, Azure Blob Storage, Amazon S3, Box, Dropbox, Google Cloud Storage), free web hosting apps (Weebly, Squarespace), free file sharing services (DocPlayer, MediaFire, WeTransfer), and free source code hosting apps (GitHub, SourceForge). Because these apps all provide low-cost or no-cost file hosting, I would expect them and similar apps to continue to be abused for malware and phishing delivery for the foreseeable future.
Mitigating the threat
In the face of these two most common attack vectors, organizations can mitigate the threat by:
- Directing employees to apps with a legitimate business purpose: Security teams should create a review and approval process for new apps and implement a continuous monitoring process that will alert them when apps are being misused or have been compromised.
- Educating and raising awareness with employees: This can come through both annual training and real-time user training, helping to coach employees in the moment before they click the link or access an unauthorized application.
- Using intelligent tools: Along with real-time user training, security teams should be routinely scanning HTTP/HTTPS traffic, while also using a cloud access security broker (CASB), secure web gateway (SWG) and data loss prevention (DLP) tools.
While it will be impossible to prevent employees from ever clicking a nefarious link, by implementing the steps above, businesses can go a long way in managing the risk.
To find out more about Netskope Threat Labs research into cloud threats like social engineering read our latest Cloud and Threat Report “2023 Year in Review.”