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About targeted attack e-mail

What is targeted attack e-mail?

Targeted attack e-mail is e-mail used to steal important information from the recipient’s organization with a virus skilfully incorporated in it so that the recipient will open it believing it is e-mail concerning the work of the organization he belongs to.
Simply by opening a file attached to a targeted attack e-mail or clicking on a link in this e-mail, employees or staff of companies and organizations have infected their computers with a virus that steals information, resulting in the leakage of confidential information.
Because viruses in targeted attack e-mail in particular often cannot be detected by virus protection software, there have been cases where it was difficult for users to notice infection, resulting in the damage expanding before they know what’s happening.

What are targeted attack e-mail protection measures?

Be wary of attached files or URL in suspicious e-mail.

It is important to be careful not to open attached files or click on links of suspicious e-mail after you have received it.
And attack e-mail may be sent with the sender’s e-mail address falsely shown as a legitimate domain.
In this case, cautiously checking the sender’s address on e-mail and using sender domain certification functions to make sure that the e-mail was sent from the correct address are effective ways to spot suspicious e-mail.

Being wary of the text of e-mail

Posing as senders of e-mail with whom the recipient exchanges business e-mail, or faking e-mail subject lines, recipients, contents, format of attached files, signatures etc. that are often used are the major ways of tricking recipients.
A characteristic is that it is difficult to notice suspicious points at a glance, but it is important to make judgments based on your most recent e-mail exchange in order to confirm that such e-mail is targeted attack e-mail.
∗ Characteristics of this e-mail include mixed Japanese and another language, or incorrect use of Japanese particles.
It is also necessary to be wary when e-mail suddenly arrives from a sender with whom you have not recently exchanged e-mail or e-mail with contents totally unrelated to the topics of recent e-mail exchanges.

When you have received such suspicious e-mail, immediately report it to and discuss it with your system manager.


There has been a recent increase in the frequency of targeted attack mail with malware in an attached file sent using free e-mail addresses which anyone can obtain, so it is necessary to be particularly wary of e-mail sent from a free e-mail address.
Generally, the absolutely minimal measures necessary in order to minimize the danger of infection by a virus is to use virus protection software and to always update your software.

Last-Modified: August 18, 2017

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