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How to Prevent Account Takeover Attacks
Account takeover attacks – accessing someone else’s online account for malicious purposes – continue to be one of the fastest-growing security threats faced by organizations today.
Account takeover happens as a result of inadvertently exposing account login details or through malicious account takeover via botnets. The account takeover of an account owned by SSL certificate issuer Comodo is an example of account takeover as a result of inadvertently exposing account login details.
Netherlands-based security researcher Jelle Ursem told TechCrunchthat Comodo’s email address and password were inadvertently left exposed in a public GitHub repository owned by a Comodo software developer. This enabled Ursem to login to Comodo’s Microsoft-hosted cloud services containing sensitive information of the company. The said account wasn’t protected with two-factor authentication. Ursem said he contacted Comodo about the exposed account.
When contacted by TechCrunch, Comodo said, “The data accessed was not manipulated in any way and within hours of being notified by the researcher, the account was locked down.” Ursem, however, told TechCrunch, “This account has already been hacked by somebody else, who has been sending out spam.”
Account Takeover Botnets
While many malicious actors are opportunistic, that is, while many abused inadvertently exposed account login details, many just don’t wait for these opportunities to come. Many of today’s malicious actors are aggressively taking over accounts through botnets.
In the Sixth Annual Fraud Attack Index, Forter found that there had been a 45% increase in account takeover attacks by the end of 2018 compared to the beginning of 2017. One of the means by which malicious actors perpetuated account takeover attacks is thorough bots, Forter found.
“Fraudsters often try to hide their activities behind these devices [bots], flying under the radar of detection for most legacy fraud prevention systems, which are simply not equipped with sophisticated enough technology to pick up on the nuances of these behavioural indicators and the personas hiding behind them,” Forter said.
Botnet, also known as bot, refers to a group of computers infected with malicious software (malware) that allows an attacker to control this group of infected computers as one army for malicious activities. Many of these botnets have been used by attackers as an army for distributed denial-of-service (DDoS) attacks and illicit cryptocurrency mining. Malicious actors are increasingly using these botnets for account takeover attacks.
An account takeover botnet works by installing a credential cracking malware on compromised computers. These infected computers are then controlled by an attacker or attackers to login into an account of banking site, social network or email. Once the correct username and password combination is cracked, the account taken over is then used by attackers to steal money (in case of a banking site), steal confidential information such as credit card information, or purchase goods and services.
Between April 7th to April 22nd this year, Impervaobserved the account takeover attacks carried out by a botnet, composed of an enslaved army of 2,500 infected computers – with a corresponding 2,500 IPs overall – that attacked more than 300 sites while active. Each day during the attack period, 800 IPs were actively attacking 30 sites with 150,000 login attempts, Imperva found.
From the victim site perspective, each site was attacked for 7 hours by 500 IPs sending 7,000 login attempts with 7,000 different login details (usernames and passwords); and from a single site perspective, each botnet-controlled IP was responsible for approximately 14 login attempts during the attack time, or approximately 2 login attempts per hour, Imperva found.
The above-mentioned method of attack is called a “low and slow” attack – whereby the botnet enslaves a lot of computers, each sending only a small number of requests, to cover-up the attack as legitimate traffic. Distributing the account takeover attacks across many infected computers or IP addresses makes these attacks go without being detected.
The usernames and passwords used in the login attempts for account takeover attacks often come from credential cracking and credential stuffing. In credential cracking, every word in the dictionary is tried to crack the correct username and password combination. In credential stuffing, the attackers exploit users’ tendency to reuse passwords across multiple sites.
Credential stuffing was cited by StubHubas the reason why a “small number” of users’ accounts had been illegally taken over by fraudsters. In the StubHub case, attackers illegally took over 1,000 StubHub users’ accounts and used these compromised accounts to buy thousands of high-value tickets, including tickets to Justin Timberlake and Elton John concerts, Yankees baseball games, U.S. Open tennis matches and Broadway shows. The account takeover attackers then resold these tickets for a profit of more than a million dollars.
Traditional security solutions have proven to be ineffective in “low and slow” account takeover attacks using botnets. By using account takeover botnets, malicious actors spread the attack via thousands of compromised computers or IPs, making them go undetected for a long period of time.
Choosing a strong username and password combination via eliminating the use of dictionary words, using a unique username and password combination for every account and the use of multi-factor authentication are some of the best cyber security practices in preventing account takeover attacks.
Malicious actors, however, are always finding creative ways to crack those unique and strong usernames and passwords and even multi-factor authentication. An automated security solution that monitors abnormal access to these accounts is one of the mitigating measures against account takeover attacks.
When you need help minimizing cybersecurity risks, our team of experts will answer the questions you have and will help you protect your data. Contact ustoday.
Steve E. Driz, I.S.P., ITCP