As the use of packers and obfuscation techniques by attackers grows and its complexities become more widespread, 29% of malware captured was previously unknown, reveals a new study by HP.
About 88% of malware was delivered by email into users’ inboxes, in many cases having bypassed gateway filters, and web downloads accounted for the remaining 12%, reveals HP’s latest Quarterly Threat Insights Report, which analyses real-world attacks worldwide. On average, it took 8.8 days for threats to become known by hash to antivirus engines, essentially offering hackers over a week’s ‘head-start’ to further their campaigns.
“This report highlights the deficiencies in traditional defences that rely on detection to block malware. Attackers have repeatedly found new ways to bypass traditional detection-based tools, making it more important than ever for organizations to build zero-trust design principles into their security architecture,” said Dr. Ian Pratt, Global Head of Security for Personal Systems at HP.
The report reviews notable malware trends identified by HP Sure Click, a threat-alert software, from October-December 2020.
Some of the notable threats are:
Web Browser exploits leading to FickerStealer: It is a malware campaign targeting misspelled domains of popular instant messaging services. It leads visitors to RigEK landing pages that attempt to exploit web browser and plugin vulnerabilities to infect visitors’ PCs with information-stealing malware called FickerStealer.
Delivery-themed lures tempting users into letting the RATs in: APOMacroSploit, a new Office malware builder, was used to target victims in delivery-themed spam campaigns, tricking them into opening weaponized XLS attachments, which ultimately direct them to the BitRAT remote access Trojan being deployed on their computers.
The return of ZLoader: Sure Click noticed an increase in ZLoader banking Trojan activity. It leveraged a combination of techniques including Word documents masquerading as pharmaceutical invoices that run malicious macros only after the document has been closed.
The art of misdirection through DOSfuscation: Emotet, just before it was shut down in January 2021, would modify the downloader using DOSfuscation techniques to make its obfuscation more complex. The downloader would bring up an error message when opened, helping to avoid suspicion from users when the malicious documents didn’t behave as expected.
Email thread hijacking of government targets: The HP software stopped email thread hijacking attacks against government organizations in Central America, where stolen email data was used to craft convincing phishing lures to distribute Emotet.
“Cybercriminals are exploiting low-cost malware-as-a-service kits, which are proliferating in underground forums. Kits like APOMacroSploit, which emerged in Q4 2020, can be bought for as little as $50 USD, illustrating just how low the barrier to entry is for opportunistic cybercrime. We have also seen threat actors continue to experiment with malware delivery techniques to improve their chances of establishing footholds into networks. The most effective execution techniques we saw in Q4 2020 involved old technologies like Excel 4.0 macros that often offer little visibility to detection tools,” said Alex Holland, senior malware analyst at HP.
The fourth quarter of 2020 witnessed a significant increase in malicious spam distributing Dridex malware, more than tripled from Q3, representing a 239% increase. Dridex was the second most widely circulating crimeware family behind Emotet. It first originated in 2012 as a banking Trojan, but has shifted its focus to extorting money from victims using ransomware since 2017.
Trojans accounted for 66% of malware samples analysed. The most common type of malicious attachments were documents (31%), archive files (28%), spreadsheets (19%) and executable files (17%), the report said.
Malicious executables rose by 12%, with CVE-2017-11882 – a memory corruption flaw in Microsoft Office’s Equation Editor – accounting for nearly three-quarters of the exploits. It also noted a 12% growth in malware that exploits CVE-2017-0199, which is commonly used to run malicious scripts to deploy malware when a user opens an Office document.