Yubikey WSL: Agent refused operation

I recently had problems using my Yubikey GPG key to SSH from my WSL instance to a linux server. After the usual checks, it seemed like it was a client side error sign_and_send_pubkey: signing failed for RSA "/home/user/.ssh/id_rsa" from agent: agent refused operation. Most people on the ...

SANS SEC760 Review

I wasn't expecting to do yet another SANS course but the opportunity did arise for me to do SEC760 in ondemand format. Previously, I had already done SEC660 as well as OSCE and was conversant with buffer overflows in a multitude of formats (EIP overrides, SEH overrides, ASLR/DEP bypass, return ...

Phishing SMS/Emails/Calls

The Cyber Security Agency (CSA) posted an advisory about tech support scammers impersonating CSA officers 7 months ago. A few cybersecurity professional, me included, saw the post and immediately commented either directly on the post or on a copy shared by one of the deputy directors that the ...

Azure Resource Manager - Service Principal (Manual)

I had some issues with automatically creating a service principal to set up Azure Resource Manager in Azure DevOps due to overly strict Azure AD policies resulting in the following error Error encountered: Failed to create an app in Azure Active Directory. Error: Credential lifetime exceeds the ...

Yubikey passwordless Windows local account login

Yubico used to publish a Windows Store application YubiKey for Windows Hello that allowed local non-domain joined accounts to login to Windows simply by inserting the YubiKey. However, that application has since been retired and there is no current method to perform a password login for a local ...

Converting WinExec shellcode

I have found an interesting method to convert WinExec shellcode. This may be useful if WinExec cannot be used because the characters WinE are bad characters or if there are security solutions monitoring for its execution. This method requires msvcrt.dll to be loaded as it uses the system call ...

Digital NRIC Spoofing

Pretty interesting how easy it is to spoof the animated hologram thingy in the new Digital NRIC. Managed to build a Proof of Concept (POC) within a few hours of the news release. Govtech's response is as follow: Hi Benjamin, We refer your report submitted under the Vulnerability Disclosure ...

Industry Consultation on Licensing for CSPs

Below feedback was submitted to CSA on 11 Oct 2021 in an individual capacity. Q1 I refer to item 7 on page 6 of Annex A: Industry Consultation Document, reproduced below. If a company registered in Singapore or an individual residing and working in Singapore is only providing cybersecurity ...