security

Be Careful With Fake Zoom Client Downloads Miscreants are tricking victims into downloading fake Zoom clients (and likely other meeting software) by first sending them fake meeting invites that direct victims to a page that offers malware for download as an update to the Zoom client. https://isc.sans.edu/diary/Be%20Careful%20With%20Fake%20Zoom%20Client%20Downloads/32014 Python tarfile Vulnerability Recently, the Python tarfile module […]

Phishing e-mail that hides malicious links from Outlook users Jan found a phishing email that hides the malicious link from Outlook users. The email uses specific HTML comment clauses Outlook interprets to render or not render specific parts of the email s HTML code. Jan suggests that the phishing email is intented to not expose […]

vBulletin Exploits CVE-2025-48827, CVE-2025-48828 We do see exploit attempts for the vBulletin flaw disclosed about a week ago. The flaw is only exploitable if vBulltin is run on PHP 8.1, and was patched over a year ago. However, vBulltin never disclosed the type of vulnerability that was patched. https://isc.sans.edu/diary/vBulletin%20Exploits%20%28CVE-2025-48827%2C%20CVE-2025-48828%29/32006 Google Chrome 0-Day Patched Google released […]

Simple SSH Backdoor Xavier came across a simple SSH backdoor taking advantage of the ssh client preinstalled on recent Windows systems. The backdoor is implemented via an SSH configuration file that instructs the SSH client to connect to a remote system and forward a shell on a random port. This will make the shell accessible […]

A PNG Image With an Embedded Gift Xavier shows how Python code attached to a PNG image can be used to implement a command and control channel or a complete remote admin kit. https://isc.sans.edu/diary/A+PNG+Image+With+an+Embedded+Gift/31998 Cisco IOS XE WLC Arbitrary File Upload Vulnerability (CVE-2025-20188) Analysis Horizon3 analyzed a recently patched flaw in Cisco Wireless Controllers. This […]

Alternate Data Streams: Adversary Defense Evasion and Detection Good Primer of alternate data streams and how they are abused, as well as how to detect and defend against ADS abuse. https://isc.sans.edu/diary/Alternate%20Data%20Streams%20%3F%20Adversary%20Defense%20Evasion%20and%20Detection%20%5BGuest%20Diary%5D/31990 Connectwise Breach Affects ScreenConnect Customers Connectwise s ScreenConnect solution was compromised, leading to attacks against a small number of customers. This is yet another […]

Exploring a Use Case of Artificial Intelligence Assistance with Understanding an Attack Jennifer Wilson took a weird string found in a recent honeypot sample and worked with ChatGPT to figure out what it is all about. https://isc.sans.edu/diary/%5BGuest%20Diary%5D%20Exploring%20a%20Use%20Case%20of%20Artificial%20Intelligence%20Assistance%20with%20Understanding%20an%20Attack/31980 Ransomware Deployed via SimpleHelp Vulnerabilities Ransomware actors are using vulnerabilities in SimpleHelp to gain access to victim s […]

SSH authorized_keys File One of the most common techniques used by many bots is to add rogue keys to the authorized_keys file, implementing an SSH backdoor. Managing these files and detecting unauthorized changes is not hard and should be done if you operate Unix systems. https://isc.sans.edu/diary/Securing%20Your%20SSH%20authorized_keys%20File/31986 REMOTE COMMAND EXECUTION ON SMARTBEDDED METEOBRIDGE (CVE-2025-4008) Weatherstation software […]

SVG Steganography Steganography is not only limited to pixel-based images but can be used to embed messages into vector-based formats like SVG. https://isc.sans.edu/diary/SVG%20Steganography/31978 Fortinet Vulnerability Details CVE-2025-32756 Horizon3.ai shows how it was able to find the vulnerability in Fortinet s products, and how to possibly exploit this issue. The vulnerability is already being exploited in […]