I published the following diary on isc.sans.edu: “Weaponized RTF Document Generator & Mailer in PowerShell“: Another piece of malicious PowerShell script that I found while hunting. Like many malicious activities that occur in those days, it is related to the COVID19 pandemic. Its purpose of simple: It checks if Outlook
I published the following diary on isc.sans.edu: “PowerShell Sample Extracting Payload From SSL“: Another diary, another technique to fetch a malicious payload and execute it on the victim host. I spotted this piece of Powershell code this morning while reviewing my hunting results. It implements a very interesting technique. As usual,
Bad guys are always trying to use “exotic” file extensions to deliver their malicious payloads. If common dangerous extensions are often blocked by mail security gateways, there exists plenty of less common extensions. These days, with the COVID19 pandemic, we are facing a peak of phishing and scams trying to
I published the following diary on isc.sans.edu: “Obfuscated with a Simple 0x0A“: With the current Coronavirus pandemic, we continue to see more and more malicious activity around this topic. Today, we got a report from a reader who found a nice malicious Word document part of a Coronavirus phishing campaign. I
I published the following diary on isc.sans.edu: “Malicious JavaScript Dropping Payload in the Registry“: When we speak about “fileless” malware, it means that the malware does not use the standard filesystem to store temporary files or payloads. But they need to write data somewhere in the system for persistence or
I published the following diary on isc.sans.edu: “Very Large Sample as Evasion Technique?“: Security controls have a major requirement: they can’t (or at least they try to not) interfere with normal operations of the protected system. It is known that antivirus products do not scan very large files (or just
I published the following diary on isc.sans.edu: “COVID-19 Themed Multistage Malware“: More and more countries are closing their borders and ask citizens to stay at home. The COVID-19 virus is everywhere and also used in campaigns to lure more victims who are looking for information about the pandemic. I found
I published the following diary on isc.sans.edu: “Agent Tesla Delivered via Fake Canon EOS Notification on Free OwnCloud Account“: For a few days, there are new waves of Agent Tesla landing in our mailboxes. I found one that uses two new “channels” to deliver the trojan. Today, we can potentially receive
I published the following diary on isc.sans.edu: “A Safe Excel Sheet Not So Safe“: I discovered a nice sample yesterday. This excel sheet was found in a mail flagged as “suspicious†by a security appliance. The recipient asked to release the mail from the quarantine because “it was sent from
I published the following diary on isc.sans.edu: “Simple but Efficient VBScript Obfuscation“: Today, it’s easy to guess if a piece of code is malicious or not. Many security solutions automatically detonate it into a sandbox by security solutions. This remains quick and (most of the time still) efficient to have a first
