Malware spam more than tripled in August compared to July's figures, whilst overall spam made up 92.51 per cent of all emails last month, according to a new security report.
Many threats came in the form of .zip attachment spam, which saw a four-fold increase month-over-month, while messages containing .html attachments with malicious JavaScript also spiked, according to Symantec.
Much of the .zip attachment spam contained Trojan.Zbot, designed to steal confidential data such as bank details from targets.
Trojan.Sasfis was also detected by Symantec as prevalent in these messages, attempting to download and execute malicious content, and spammers were trying to spread this Trojan horse by varying fake shipping or delivery services.
The malicious JavaScript in the .html files, meanwhile, was capable of exploiting browsers and plug-in vulnerabilities to run arbitrary code, hijack browsing sessions or steal data.
In geographical divides, five per cent of all spam originated from the UK in August, showing no change over July, but spam coming from the US went up from 22 per cent to 24 per cent.
As for what subject lines spammers ran with in August, "Your wife photos attached" was the most popular.
Phish me out
The US was not only the top nation for sending spam it also kept its unenviable title of the king of phishing.
The country is home to more than half of all phishing hosts, while the UK has only four per cent, Symantec figures showed.
In terms of what sectors phishers were looking to exploit, the financial sector dwarfed all other industries, targeted by 87 per cent of attacks.
