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Phone scams impersonating Australian businesses and government agencies   Alert

Aug 13, 2020 - Cybercriminals are spoofing Australian mobile numbers and pretending to be from an Australian Government agency, delivery company or business, manipulating the individual to gain access to their device.

Iranian Islamic Revolutionary Guard Corps-Affiliated Cyber Actors Exploiting Vulnerabilities for Data Extortion and Disk Encryption for Ransom Operations   Advisory

Sep 15, 2022 - The Australian Signals Directorate's Australian Cyber Security Centre (ASD's ACSC) has joined with international cyber security agency partners to co-author an advisory on continued Iranian state-sponsored cyber threats. Organisations are encouraged to apply the recommended mitigations to protect themselves online.

Phone and email scammers impersonating the ASD's ACSC   Alert

Jan 19, 2022 - The Australian government will NEVER phone you to request access to your computer, or request you to purchase cryptocurrencies or gift cards. If you receive a suspicious phone call, take the caller's details, hang up and contact the company they claim to represent via official communication channels listed on their website. Never call a number provided by the scammer.

Security configuration guide: Samsung Galaxy S10, S20 and Note 20 devices   Publication

Oct 6, 2021 - ASD has developed this guide to assist Australian’s to understand risks when deploying Samsung Galaxy and Samsung Note devices and the security requirements that need to be met to allow them to handle classified data.

Remote code execution vulnerability present in Samba versions prior to 4.13.17   Alert

Feb 4, 2022 - A vulnerability (CVE-2021-44142) has been identified in Samba versions prior to 4.13.17. Exploitation of this vulnerability could allow a malicious cyber actor to perform privileged remote code execution. Affected Australian organisations should apply the available patch, including affected software vendors.

Secure your email   Guidance

Jul 29, 2024 - How to protect yourself when using email and reduce spam and malicious emails.

Guidelines for email   Advice

Dec 4, 2025 - This chapter of the Information security manual (ISM) provides guidance on email.

Microsoft Exchange Server security best practices   Publication

Oct 31, 2025 - This paper—authored by the National Security Agency (NSA), Cybersecurity and Infrastructure Security Agency (CISA), Australian Signals Directorate’s Australian Cyber Security Centre (ASD’s ACSC), and Canadian Centre for Cyber Security (Cyber Centre)—provides security best practices for administrators on hardening on-premises (on-prem) Exchange.

How to combat fake emails   Publication

Oct 6, 2021 - Organisations can reduce the likelihood of their domains being used to support fake emails by implementing Sender Policy Framework (SPF) and Domain-based Message Authentication, Reporting and Conformance (DMARC) records in their Domain Name System (DNS) configuration. Using DMARC with DomainKeys Identified Mail (DKIM) to sign emails provides further safety against fake emails. Likewise, organisations can better protect their users against fake emails by ensuring their email systems use and apply SPF, DKIM and DMARC policies on inbound email.

Marketing and filtering email service providers   Publication

Oct 6, 2021 - This publication provides high level guidance on how to use email service providers (ESPs) in particular deployment scenarios. The considerations and controls described in that publication also apply to ESPs sending email on other organisations’ behalf.

Gateway security guidance package: Gateway technology guides   Publication

Jul 29, 2025 - This guidance is one part of a package of documents that forms the gateway security guidance package. When designing, procuring, operating, maintaining or disposing of a gateway, it is important to consider all the documents from the gateway security guidance package at different stages of governance, design and implementation, and not to consume this guidance in isolation.

COVID-19 themed malicious cyber activity   Advisory

Mar 27, 2020 - This update is designed to raise awareness of increasing COVID-19 themed malicious cyber activity, and provide practical cyber security advice that organisations and individuals can follow to reduce the risk of being impacted.

Threat update: COVID-19 malicious cyber activity 27 March 2020   Advisory

Mar 27, 2020 - This update is designed to raise awareness of increasing COVID-19 themed malicious cyber activity, and provide practical cyber security advice that organisations and individuals can follow to reduce the risk of being impacted.

Malicious email mitigation strategies   Publication

Oct 6, 2021 - Socially engineered emails containing malicious attachments and embedded links are routinely used in targeted cyber intrusions against organisations. This publication has been developed to provide mitigation strategies for the security risks posed by these malicious emails.

Bulletproof defense: mitigating risks from bulletproof hosting providers   Publication

Nov 20, 2025 - This document provides internet service providers (ISPs) and network defenders recommendations to mitigate potential cybercriminal activity enabled by bulletproof hosting (BPH) providers.

Advisory 2020-017: Resumption of Emotet malware campaign   Advisory

Oct 30, 2020 - The Australian Signals Directorate’s Australian Cyber Security Centre (ACSC) has observed the resumption of an ongoing and widespread campaign of malicious emails designed to spread the Emotet malware across a variety of sectors in the Australian economy, including critical infrastructure providers and government agencies.

How to protect yourself from malware   Guidance

Nov 10, 2023 - Malware (short for 'malicious software') is software that cybercriminals use to harm your computer system or network. Cybercriminals can use malware to gain access to your computer without you knowing, in targeted or broad-based attacks.

Artificial intelligence and machine learning: Supply chain risks and mitigations   Publication

Oct 16, 2025 - This guidance is intended for organisations and staff that deploy or develop AI or ML systems and components.

Email security  

Jul 29, 2024 - Protect yourself, your employees and business from an email security incident before it's too late.

Easy steps to secure yourself online   Guidance

Apr 7, 2021 - Reduce the risk of being targeted by cybercriminals by following these easy steps.