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 Read More

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 Read More

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 Read More

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 Read More

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 Read More

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 Read More

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 Read More

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 Read More

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 Read More

Resilient Secure Backup Connectivity for SMB/Home Users Establishing resilient access to a home network via a second ISP may lead to unintended backdoors. Secure the access and make sure you have the visibility needed to detect abuse. https://isc.sans.edu/diary/Resilient%20Secure%20Backup%20Connectivity%20for%20SMB%20Home%20Users/31972 BadSuccessor: Abusing dMSA to Escalate Privileges in Active Directory An attacker with Read More

New Variant of Crypto Confidence Scam Scammers are offering login credentials for what appears to be high value crypto coin accounts. However, the goal is to trick users into paying for expensive VIP memberships to withdraw the money. https://isc.sans.edu/diary/New%20Variant%20of%20Crypto%20Confidence%20Scam/31968 Malicious Chrome Extensions Malicious Chrome extensions mimick popular services like VPNs Read More

Researchers Scanning the Internet A newish RFC, RFC 9511, suggests researchers identify themselves by adding strings to the traffic they send, or by operating web servers on machines from which the scan originates. We do offer lists of researchers and just added three new groups today https://isc.sans.edu/diary/Researchers%20Scanning%20the%20Internet/31964 Cloudy with a Read More

RAT Dropped By Two Layers of AutoIT Code Xavier explains how AutoIT was used to install a remote admin tool (RAT) and how to analyse such a tool https://isc.sans.edu/diary/RAT%20Dropped%20By%20Two%20Layers%20of%20AutoIT%20Code/31960 RVTools compromise confirmed Robware.net, the site behind the popular tool RVTools now confirmed that it was compromised. The site is currently Read More

xorsearch.py: Python Functions Didier s xorsearch tool now supports python functions to filter output https://isc.sans.edu/diary/xorsearch.py%3A%20Python%20Functions/31858 Pwn2Own Berlin 2025 Last weeks Pwn2Own contest in Berlin allowed researchers to demonstrate a number of new exploits with a large focus on privilege escalation and virtual machine escape. https://www.zerodayinitiative.com/blog/2025/5/17/pwn2own-berlin-2025-day-three-results Senior US Officials Impersonated in Read More

Web Scanning SonicWall for CVE-2021-20016 - Update Scans for SonicWall increased by an order of magnitude over the last couple of weeks. Many of the attacks appear to originate from Global Host , a low-cost virtual hosting provider. https://isc.sans.edu/diary/Web%20Scanning%20SonicWall%20for%20CVE-2021-20016%20-%20Update/31952 Google Update Patches Exploited Chrome Flaw Google released an update for Read More

Another day, another phishing campaign abusing google.com open redirects Google s links from it s maps page to hotel listings do suffer from an open redirect vulnerability that is actively exploited to direct users to phishing pages. https://isc.sans.edu/diary/Another%20day%2C%20another%20phishing%20campaign%20abusing%20google.com%20open%20redirects/31950 Adobe Patches Adobe patched 12 different applications. Of particular interest is the Read More

Microsoft Patch Tuesday Microsoft patched 70-78 vulnerabilities (depending on how you count them). Five of these vulnerabilities are already being exploited. In particular, a remote code execution vulnerability in the scripting engine should be taken seriously. It requires the Microsoft Edge browser to run in Internet Explorer mode. https://isc.sans.edu/diary/Microsoft%20Patch%20Tuesday%3A%20May%202025/31946 Security Read More

Apple Updates Everything Apple patched all of its operating systems. This update ports a patch for a recently exploited vulnerability to older versions of iOS and macOS. https://isc.sans.edu/diary/31942 It Is 2025, And We Are Still Dealing With Default IoT Passwords And Stupid 2013 Router Vulnerabilities Versions of the Mirai botnet Read More

Steganography Challenge Didier revealed the solution to last weekend s cryptography challenge. The image used the same encoding scheme as Didier described before, but the columns and rows were transposed. https://isc.sans.edu/forums/diary/Steganography%20Challenge%3A%20My%20Solution/31912/ FBI Warns of End-of-life routers The FBI is tracking larger botnets taking advantage of unpatched routers. Many of these Read More

No Internet Access: SSH to the Rescue If faced with restrictive outbound network access policies, a single inbound SSH connection can quickly be turned into a tunnel or a full-blown VPN https://isc.sans.edu/diary/No%20Internet%20Access%3F%20SSH%20to%20the%20Rescue!/31932 SAMSUNG magicINFO 9 Server Flaw Still exploitable The SAMSUNG magicINFO 9 Server Vulnerability we found being exploited last Read More