Hancitor Making Use of Cookies to Prevent URL Scraping

Tips & Advice

This blog was written by Vallabh Chole & Oliver Devane

Over the years, the cybersecurity industry has seen many threats get taken down, such as the Emotet takedown in January 2021. It doesn’t usually take long for another threat to attempt to fill the gap left by the takedown. Hancitor is one such threat.

Like Emotet, Hancitor can send Malspams to spread itself and infect as many users as possible. Hancitor’s main purpose is to distribute other malware such as FickerStealer, Pony, CobaltStrike, Cuba Ransomware and Zeppelin Ransomware. The dropped Cobalt Strike beacons can then be used to move laterally around the infected environment and also execute other malware such as ransomware.

This blog will focus on a new technique used by Hancitor created to prevent crawlers from accessing malicious documents used to download and execute the Hancitor payload.

The infection flow of Hancitor is shown below:

A victim will receive an email with a fake DocuSign template to entice them to click a link. This link leads him to feedproxy.google.com, a service that works similar to an RSS Feed and enables site owners to publish site updates to its users.

When accessing the link, the victim is redirected to the malicious site. The site will check the User-Agent of the browser and if it is a non-Windows User-Agent the victim will be redirected to google.com.

If the victim is on a windows machine, the malicious site will create a cookie using JavaScript and then reload the site.

The code to create the cookie is shown below:

The above code will write the Timezone to value ‘n’ and the time offset to UTC in value ‘d’ and set it into cookie header for an HTTP GET Request.

For example, if this code is executed on a machine with timezone set as BST the values would be:

d = 60

n = “Europe/London”

These values may be used to prevent further malicious activity or deploy a different payload depending on geo location.

Upon reloading, the site will check if the cookie is present and if it is, it will present them with the malicious document.

A WireShark capture of the malicious document which includes the cookie values is shown below:

The document will prompt them to enable macros and, when enabled, it will download the Hancitor DLL and then load it with Rundll32.

Hancitor will then communicate with its C&C and deploy further payloads. If running on a Windows domain, it will download and deploy a Cobalt Strike beacon.

Hancitor will also deploy SendSafe which is a spam module, and this will be used to send out malicious spam emails to infect more victims.

Conclusion

With its ability to send malicious spam emails and deploy Cobalt Strike beacons, we believe that Hancitor will be a threat closely linked to future ransomware attacks much like Emotet was. This threat also highlights the importance of constantly monitoring the threat landscape so that we can react quickly to evolving threats and protect our customers from them.

IOCs, Coverage, and MITRE

IOCs

IOC Type IOC Coverage Content Version
Malicious Document SHA256 e389a71dc450ab4077f5a23a8f798b89e4be65373d2958b0b0b517de43d06e3b W97M/Dropper.hx 4641
Hancitor DLL SHA256 c703924acdb199914cb585f5ecc6b18426b1a730f67d0f2606afbd38f8132ad6 Trojan-Hancitor.a 4644
Domain hosting Malicious Document URL http[:]//onyx-food[.]com/coccus.php RED N/A
Domain hosting Malicious Document URL http[:]//feedproxy[.]google[.]com/~r/ugyxcjt/~3/4gu1Lcmj09U/coccus.php RED N/A

Mitre

Technique ID Tactic Technique details
T1566.002 Initial Access Spam mail with links
T1204.001 Execution User Execution by opening link.
T1204.002 Execution Executing downloaded doc
T1218 Defence Evasion Signed Binary Execution Rundll32
T1055 Defence Evasion Downloaded binaries are injected into svchost for execution
T1482 Discovery Domain Trust Discovery
T1071 C&C HTTP protocol for communication
T1132 C&C Data is base64 encoded and xored

Articles You May Like

Partner sessions are going all out at TC Sessions: SaaS 2021
Before and After a Pen Test: Steps to Get Through It
Brave browser replaces Google with its own search engine
Be on the Lookout for a New Wave of QR Code Scams
CISA Issues Warning On Cyber Threats Targeting Water and Wastewater Systems

Leave a Reply

Your email address will not be published. Required fields are marked *