How Cybercriminals Target Cryptocurrency?

Written by Sherrod DeGrippo, Vice President for Threat Research and Detection at Proofpoint

As cryptocurrency and non-fungible tokens (NFTs) become more mainstream, and capture headlines for their volatility, there is a greater likelihood of more individuals falling victim to fraud attempting to exploit people for digital currencies. The rise and proliferation of cryptocurrency have also provided attackers with a new method of financial extraction. It’s commonly believed that cryptocurrency provides more anonymity via less governmental and organizational oversight and visibility coupled with the inherent fungibility, thus making it an appealing financial resource for threat actors. The financially motivated attacks targeting cryptocurrency have largely coalesced under pre-existing attack patterns observed in the phishing landscape prior to the rise of blockchain based currency.

Proofpoint researchers observe multiple objectives demonstrated by cybercriminal threat actors relating to digital tokens and finance such as traditional fraud leveraging business email compromise (BEC) to target individuals, and activity targeting decentralized finance (DeFi) organizations that facilitate cryptocurrency storage and transactions for possible follow-on activity. Both of these threat types contributed to a reported $14 billion in cryptocurrency losses in 2021. In fact, Business Email Compromise topped the list of types of attacks CISOs in UAE expect to face in the coming months with 35% of CISO’s being concerned of potential BEC attacks.

While most attacks require a basic understanding of how cryptocurrency transfers and wallets function, they do not require sophisticated tooling to find success. Common techniques observed when targeting cryptocurrency over email include credential harvesting, the use of basic malware stealers that target cryptocurrency credentials and cryptocurrency transfer solicitation like BEC. These techniques are viable methods of capturing sensitive values which facilitate the transfer and spending of cryptocurrency.

There are multiple DeFi applications and platforms – such as cryptocurrency exchanges – that people can use to manage their cryptocurrency. These platforms often require usernames and passwords, which are potential targets for financially motivated threat actors.

Despite public keys being “safe” to share, researchers are seeing actors solicit the transfer of cryptocurrency funds via BEC type emails that include threat actor-controlled public keys and cryptocurrency addresses. These email campaigns rely on social engineering to secure the transfer of funds from targeted victims.

Credential Harvesting and Cryptocurrency

In 2022 Proofpoint has observed regular attempts to compromise user’s cryptocurrency wallets using credential harvesting. This method often relies on the delivery of a URL within an email body or formatted object which redirects to a credential harvesting landing page. Notably these landing pages have begun to solicit values utilized in the transfer and conversion of cryptocurrencies.

Crypto Phishing Kits

Credential harvesting landing pages are often built with phish kits that can be used to create multiple landing pages and used in multiple campaigns. Phish kits give threat actors the ability to deploy an effective phishing page regardless of their skill level. They are pre-packaged sets of files that contain all the code, graphics, and configuration files to be deployed to make a credential capture web page. These are designed to be easy to deploy as well as reusable. They are usually sold as a zip file and ready to be unzipped and deployed without a lot of “behind the scenes” knowledge or technical skill.

It is no wonder that CISOs around the world consider phishing as one of the most prevalent and challenging cybersecurity threats. A 2021 Proofpoint study found that almost a third of CISOs in the UAE believed they were at risk of suffering a phishing attack. Proofpoint researchers have observed multiple examples of phishing threat actors create and deploy phishing kits to harvest both login credentials to cryptocurrency related sites and cryptocurrency wallet credentials or passphrases.

Business Email Compromise – But For Crypto

A popular form of financial crime vectored through phishing is business email compromise (“BEC”). In 2022 Proofpoint regularly observes cryptocurrency transfer within the context of BEC attempts. Primarily these requests are observed in the context of employee targeting, using impersonation as a deception, and often leveraging advanced fee fraud, extortion, payroll redirect, or invoicing as themes.

The initial BEC email often contains the safe for public consumption values, including public keys and cryptocurrency addresses. By impersonating an entity known to the user and listing an actor-controlled public key or address, actors are attempting to deceive users into transferring funds from their account willingly based on social-engineering content. This is like the way actors use routing and bank account numbers during BEC phishing campaigns.

Conclusion

Financially motivated threat actor activity attempting to steal or extort cryptocurrency is not new. However, cryptocurrencies, digital tokens, and “Web3” concepts are becoming more widely known and accepted in society. Where once “crypto” was a concept that thrived in certain parts of the internet, it is now a mainstream idea, with cryptocurrency apps and services advertised by professional athletes and celebrities, and major events sponsored by cryptocurrency and block chain companies.

But threat actors are way ahead of general adoption of cryptocurrency, with existing infrastructure and ecosystems long established for stealing and using it. And as mainstream awareness and interest increases, it is more likely people will trust or engage with threat actors trying to steal cryptocurrency because they better understand how DeFi operates or are interested in being a part of “the next big thing”.

Users should be aware of common social engineering and exploitation mechanisms used by threat actors aiming to steal cryptocurrencies.