This video covers a life cycle of an Emotet infection, including initial infection, command-and-control traffic, and spambot activity sending emails with malicious spreadsheet attachments to infect new victims.
The video was recorded in a Windows Sandbox in order to avoid accidentally infecting my Windows PC with malware.
Palo Alto's Unit 42 sent out a tweet with screenshots and IOCs from an Emotet infection in early March. A follow-up tweet by Brad Duncan linked to a PCAP file containing network traffic from the infection on Malware-Traffic-Analysis.net.
Image: Screenshot of original infection email from Unit 42
- Attachment MD5: 825e8ea8a9936eb9459344b941df741a
The PCAP from Malware-Traffic-Analysis.net shows that the Excel spreadsheet attachment caused the download of a DLL file classified as Emotet.
Image: CapLoader transcript of Emotet download
- DNS: diacrestgroup.com
- MD5: 99f59e6f3fa993ba594a3d7077cc884d
Just seconds after the Emotet DLL download completes the victim machine starts communicating with an IP address classified as a botnet command-and-control server.
Image: Emotet C2 sessions in CapLoader
- C2 IP: 188.8.131.52
- C2 IP: 184.108.40.206
- C2 IP: 220.127.116.11
- JA3: 51c64c77e60f3980eea90869b68c58a8
- JA3S: ec74a5c51106f0419184d0dd08fb05bc
- JA3S: fd4bc6cea4877646ccd62f0792ec0b62
The victim PC eventually started sending out spam emails. The spam bot used TLS encryption when possible, either through SMTPS (implicit TLS) or with help of STARTTLS (explicit TLS).
Image: Emotet spambot JA3 hash in NetworkMiner Professional
- SMTPS JA3: 37cdab6ff1bd1c195bacb776c5213bf2
- STARTTLS JA3: 37cdab6ff1bd1c195bacb776c5213bf2
Below is a spam email sent from the victim PC without TLS encryption. The attached zip file contains a malicious Excel spreadsheet, which is designed to infect new victims with Emotet.
Image: Spam email extracted from Emotet PCAP with NetworkMiner
- .zip Attachment MD5: 5df1c719f5458035f6be2a071ea831db
- .xlsm Attachment MD5: 79cb3df6c0b7ed6431db76f990c68b5b
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Posted by Erik Hjelmvik on Monday, 09 May 2022 06:50:00 (UTC/GMT)