Last week, we looked at how terror groups use the Internet. Here in Part Two, we’ll take a closer look at online terrorism: the use of hacking tactics to wreak havoc.

What sort of tactics are used in cyber warfare, and how do they make any difference in the real world? Here are some of the ways that hacker groups can inflict damage via the Internet.

In the wake of the Paris terror attacks in November, hacktivist group Anonymous famously declared war on ISIS. However, cyber warfare is far from new, far from isolated, and can even result in disruption or damage for the average Internet user.

##1 ) Data Breaches ## By taking the data of a business or group and publicly leaking it, hackers can cause the loss of investors, customers or members of their target. This can prove a devastating blow, as we saw with the Ashley Madison Hack earlier in 2015.

At BreachAlarm, we sift through thousands of these spills each week, each from a variety of sources. While these are mostly ‘low-hanging fruit’ – small websites with poor security – politically-motivated hackers may also use this tactic as a means to target groups, governments or organisations.

This can cause the loss of anonymity for terrorist figures or those involved in a terrorist group. In the process, however, innocent users may find themselves exposed as ‘collateral damage’.

In the case of a compromised forum used by terrorists to plan and network, a data spill could reveal key intelligence and clues as to future targets.

##2) Doxxing## Many groups or organisations have prominent members who act as spokespeople. In order to target a specific individual, a tactic called ‘doxxing’ involves hackers leaking highly sensitive information (home address, family members, private phone number or personal email) onto the Internet.

All of these details can be gleaned through social media, social engineering, and many other tactics.

Previous victims of doxxing include an LAPD Chief, as well as celebrities like Donald Trump, Jay-Z and Mel Gibson. Other victims are simply everyday people, whose information can be found in droves on the Deep Web.

Doxxing can prove devastating to rumoured heads of terrorist organisations, as the details leaked could lead to their arrest, or even more unpredictably: vigilante action. However, if the target proves innocent, doxxing can place them in a very dangerous predicament.

##3) Social Media Overthrow## Hacking Twitter accounts has long been a staple of groups like Anonymous.

This seemingly harmless tactic can cause some disruption to terror groups, forcing them to abandon well-followed accounts and start anew. In the process, they may lose followers.

Hackers may also decide vandalise the account, posting false information in order to confuse followers, or simply publishing abusive messages.

However, this tactic’s effects are often short-lived, as new social media accounts are far too easy to create.

4) The Classic DDoS##

The act of bombarding a server with more information requests than it can handle is known as a ‘Distributed Denial of Service’ (or DDoS) attack. This kind of attack requires only a minimum of skill from an individual, making it easy for a large amount of loosely-organised activists to accomplish en-masse.

It can also be frighteningly effective: when it strikes, it can leave servers down for hours or even days. When target sites are hosted commercially, this may affect average users by causing outages across the provider’s accounts.

Such an attack, when carried out against a privately-hosted forum, is often enough to completely incapacitate the website (or its host) and force its administrators to shut it down and move elsewhere. This can effectively disrupt communication and the organisation’s ability to disseminate information to its members, costing time and effort to rebuild.

Anonymous has pulled off DDoS attacks against large organisations such as The Church of Scientology, as well as the municipal computer system of Ferguson, Missouri.

Needless to say, this hacking staple can be a nasty thorn in the side of a terror group, but has the downside of being rather brutish in its unintended consequences.

5) Hostile Account Takeovers##

Accounts on terror websites may be infiltrated by members of law enforcement or vigilante groups like Anonymous or GhostSec.

With these accounts, the hacker can gather information or even usurp the identity of the member. This can allow for a virtual undercover ‘sting’ operation, or simply a way to destroy the community from the inside out.

Terrorism in the 21st century is a deeply multi-faceted issue. Clearly, online terrorism (and counterterrorism) is no exception – and is perhaps even more complex.

It’s not just relegated to the news headlines, either. Every online strike can cut closer than you think.