Rewterz Threat Advisory – CVE-2021-30544 – Google Chrome Back-Forward Cache
June 15, 2021Rewterz Threat Alert – FormBook Malware – Active IOCs
June 15, 2021Rewterz Threat Advisory – CVE-2021-30544 – Google Chrome Back-Forward Cache
June 15, 2021Rewterz Threat Alert – FormBook Malware – Active IOCs
June 15, 2021Severity
Medium
Analysis Summary
GuLoader is currently being distributed via spam email campaigns with archived attachments that contain the malware. The majority of malware downloaded by GuLoader is commodity malware, with AgentTesla, FormBook, and NanoCore being the most predominant. This downloader typically stores its encrypted payloads on Google Drive. It has also downloaded its payloads from Microsoft OneDrive and also from compromised or attacker-controlled websites. By utilizing legitimate file-sharing websites, GuLoader can evade network-based detection, as these services are not generally filtered or inspected in corporate environments. Usually, the downloaded payloads are encrypted with a hard-coded XOR key embedded in the malware, making it difficult for file-sharing service providers to identify the payload as malicious. This time, GuLoader Shellcode injector is being distributed via a file named “EXTERNAL RFPPAN India Epoxy/PU 2021”. The scope of this campaign so far seems to be global.
Impact
- Malware installation
- Detection evasion
- Information theft
Indicators of Compromise
MD5
- 853744502b68e50e6cbaf81ffb3f5cc0
- 6aa873ee68b60704e3d00f5c885a90f7
- 99bbf83abe9d6e4ecc91493e32230833
- 7997706c97aba757d59f136484ad6833
SHA-256
- 8115607710c35c78eda8dd16d73cab92e2c857d8c91eb1422fcc1b3f06835a4a
- 32dcdbac829f1b6607c1581488a6cf95541fba686f5f81c23b9e1e79761a971b
- 2b2a00650dc91d1a7ccfa4a62e3462762c62d8a092bddb75943f87074f1d56a5
- c372ab507f3374d88dd342b524169dfa8fa91ce216b8d9257d0ae0cbccddf37b
SHA1
- ea748baebe70d7c6d3da9d1a2a34b76051425962
- c1a1601ce429cf7cb2d4c255325bf408fe69b1d5
- b0bd6ba2dc10eb5552edc7a3460c80ee0eb1b11e
- 61ab14128fb4c4b3885e5b09fd70d83eade6ca61
Remediation
- Block all threat indicators at your respective controls.
- Do not download files attached in untrusted emails.
- Do not download files from untrusted sources on the internet.
- Search for IOCs in your environment.