Relating to spam, we normally consider a bunch of completely irrelevant promoting letters, which antispam engines filter out with no bother in any respect. Nevertheless, that is removed from essentially the most disagreeable factor that may fall into your mailbox. Generally spam is used to hold out a DDoS assault on company e-mail addresses, and the sufferer will get bombarded with fully legit emails that don’t elevate any suspicion of a typical antispam engine.
Registration confirmations assault
With a purpose to carry out a mail bomb assault, attackers can exploit the registration mechanisms on the internet assets of completely unrelated firms. Utilizing automation instruments, they register on hundreds of providers from completely different international locations utilizing the sufferer’s e-mail handle. In consequence, an enormous variety of confirmations, hyperlinks to activate your account, and comparable letters find yourself in your mailbox. Furthermore, since they’re despatched by legit mail servers with fame, the antispam engine considers them authorized and doesn’t block them.
Examples of registration affirmation emails used for DDoS assaults on company e-mail addresses
As a goal the attackers normally select an handle that’s essential for the corporate’s work — one thing that’s used to speak with purchasers or companions; for instance, a mailbox of the gross sales division, technical help, or a financial institution’s handle to which functions for mortgage loans are despatched. An assault can final for days, and the plethora of emails merely overload the sufferer’s mail server and paralyze the work of the attacked division.
To efficiently shield a mailbox from such an assault, a extra refined software is required. As one of many approaches to safety towards mail bombs, we suggest utilizing the personalised content material filtering module constructed into our up to date Kaspersky Safe Mail Gateway Particularly, within the above instance of an assault by way of registration mechanisms, the operator can block letters based mostly on the presence of the phrase “registration” in numerous languages within the Topic subject (Registrace | Registracija | Registration | Registrierung | Regisztráció). In consequence, emails will probably be mechanically despatched to quarantine with out reaching the inbox and overloading the mail server.
Customized mail filter settings
In Kaspersky Safe Mail Gateway model 2.1 we’ve added the next choices for filtering incoming and outgoing mail:
- by letter dimension;
- by attachment sorts and names;
- by sender — you may specify a particular sender handle or an everyday expression;
- by recipients (together with hidden ones);
- by the presence of sure textual content within the physique of the letter (key phrases and common expressions will be added to the dictionary);
- by the presence of textual content within the topic of the letter – by key phrases, utilizing masks and common expressions, indicating particular senders;
- by X-headers.
Versatile filtering of enterprise mailings
The brand new capabilities of our resolution can be utilized not solely to guard towards e-mail bombs assaults. They can be utilized, for instance, for versatile configuration of B2B-mailout filtering. Not all staff understand every kind of enterprise mailings in the identical approach: for some it is sensible to delve into affords to buy digital elements; for others such commercials simply clog up their inboxes, whereas they think about numerous invites to take part in conferences or conduct seminars extraordinarily beneficial.
Subsequently, fully blocking legit enterprise mailouts isn’t an choice. However then again, it’s additionally not value permitting their uncontrolled supply: somebody will at all times be dissatisfied. Subsequently, Kaspersky Safe Mail Gateway doesn’t categorize such letters as spam, however lets you configure their versatile filtering by senders, recipients, textual content within the topic or physique of the letter, and so forth.
You’ll be able to be taught extra about Kaspersky Safe Mail Gateway, a part of Kaspersky Safety for Mail Servers resolution on our company web site.