A new version of the notorious Citadel banking Trojan has been uncovered targeting the financial industry, as threats to the banking world increase.
The report comes on the same day that HSBC was hit by a worldwide DDOS attack and reports that US bank Ally Financial was hit by a malicious cyber attack.
The new version is the sixth to be uncovered since Citadel was first identified in January. Security vendor RSA warned that the new version, codenamed Rain, contains a number of new features.
One of the most dangerous additions to Citadel is its new dynamic configuration mechanism. This allows Citadel's botmasters to inject malicious content into compromised browsers in real time.
The ability to change the botnet dynamically is particularly dangerous as it makes Citadel far more difficult to detect and allows the malware to spread through systems more quickly.
"The blackhat developers behind this Swiss Army knife-like Trojan are definitely stepping up cyberfraud fine-tuning with yet another unique and innovative feature added to their roster," wrote RSA Research Labs' Limor Kessem.
"Today's fraud happens in real time, so speed is of the essence. This nifty function allows Trojan operators to create web injections and use them on the fly, pushing them to selected bots without the hassle of pushing/downloading an entire new configuration file."
Citadel is a Trojan built off the older Zeus Trojan source code and is one of many being sold on underground cyber black markets.
The malware is currently known to be being sold in at least two cyber black markets, retailing for $3,391 (£2,114).
The discovery of the new Citadel version comes during an epidemic of attacks targeting financial industry.
Most recently HSBC and US Bank Ally Financial reported attacks on their networks. HSBC reported being hit by a distributed denial of service attack on Friday.
News of the attack on Ally Financial broke after Reuters reported the bank was investigating a possible breach after detecting unusual activity on its network on Thursday. At the time of publishing Ally Financial had not responded to V3's request for comment.
Prior to the attacks, the Bank of America, JPMorgan Chase and Wells Fargo's websites suffered a number of unexplained outages, believed to have been caused by cyber attacks.
The slew of attacks led the Financial Services Information Sharing and Analysis Center (FS-ISAC) to upgrade its Cyber Threat Advisory status from Elevated to High earlier in September.