Hackers Using Weaponized ZIP File To Steal NTLM Hashes

Threat actors use ZIP files to weaponize them since they can easily convey malicious payloads within compressed archives, making it difficult for security systems to detect and study the file’s contents. 

These files can be used to deliver multiple files to the target users so that attackers can take advantage of vulnerabilities or perform a number of other malicious operations as soon as these files are extracted.

Recently, the cybersecurity analysts at ANY.RUN discovered that hackers actively use the weaponized ZIP file to steal NTLM hashes.

You can analyze a malware file, network, module, and registry activity with the ANY.RUN malware sandbox, and the Threat Intelligence Lookup that will let you interact with the OS directly from the browser.

Weaponized ZIP File Steal NTLM Hashes

Cybersecurity researchers warned of a new threat between February 23, 2024, and the present moment, when they observed a mass attack on users.

Here, the complete scenario begins with the receipt of an email having a ZIP attachment and an inquiry in both English and German that says, “I sent material to your side last day have you able to get it?” Among these compressed files are two different documents, one of which turns out to be a weaponized HTML page”.

The trick here is that this HTML page is very much intricately crafted upon a 450-byte template. More specifically, redirection transfers encrypted HTTP traffic through several nodes. 

This is done with the help of Google App Script (GAS) as it receives requests from compromised systems, and this item employs the SMB protocol for its implementation. 

However, these attackers have implemented impacket-smbserver tool on their servers. It adds complexity and sophistication that points to a well-planned strategy in their cyber activities.

The following user data is obtained by the attackers when the HTML content is opened:-

• IP address
• NTLM challenge data
• Username
• Victim’s computer name

MITRE

• Phishing (T1566)
• User and PC name enumeration (T1589)
• NTLM compromise (T1187)

Queries

Here below, we have mentioned all the queries that the experts recommend:-

• SuricataID:”8001377″
• SuricataID:”8001065″
• SuricataID:”8000547″

Besides this, researchers will keep an eye on the progression of this attack in the hopes that it may enable users to examine their email attachments on the platform.

You can block malware, including Trojans, ransomware, spyware, rootkits, worms, and zero-day exploits, with Perimeter81 malware protection. All are extremely harmful, can wreak havoc, and damage your network.

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