With regards to spam, we normally consider a bunch of completely irrelevant promoting letters, which antispam engines filter out with no hassle 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 respectable emails that don’t elevate any suspicion of a regular antispam engine.
Registration confirmations assault
As a way to carry out a mail bomb assault, attackers can exploit the registration mechanisms on the net 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 tackle. Because of this, an enormous variety of confirmations, hyperlinks to activate your account, and related letters find yourself in your mailbox. Furthermore, since they’re despatched by respectable mail servers with a superb status, 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 tackle 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 tackle 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 defend a mailbox from such an assault, a extra refined device is required. As one of many approaches to safety in opposition to mail bombs, we suggest utilizing the personalised content material filtering module constructed into our up to date Kaspersky Safe Mail Gateway Specifically, within the above instance of an assault via registration mechanisms, the operator can block letters based mostly on the presence of the phrase “registration” in varied languages within the Topic area (Registrace | Registracija | Registration | Registrierung | Regisztráció). Because of this, emails will probably be routinely despatched to quarantine with out reaching the inbox and overloading the mail server.
Personalised 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’ll be able to specify a particular sender tackle or a daily 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 may 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 in opposition to e-mail bombs assaults. They can be utilized, for instance, for versatile configuration of B2B-mailout filtering. Not all workers understand all types of enterprise mailings in the identical method: for some it is sensible to delve into provides to buy digital parts; for others such commercials simply clog up their inboxes, whereas they contemplate varied invites to take part in conferences or conduct seminars extraordinarily beneficial.
Subsequently, fully blocking respectable enterprise mailouts isn’t an possibility. However however, it’s additionally not price permitting their uncontrolled supply: somebody will at all times be dissatisfied. Subsequently, Kaspersky Safe Mail Gateway doesn’t categorize such letters as spam, however permits you to configure their versatile filtering by senders, recipients, textual content within the topic or physique of the letter, and so forth.
You may be taught extra about Kaspersky Safe Mail Gateway, a part of Kaspersky Safety for Mail Servers resolution on our company web site.
