Inglês

Leia o texto para responder às questões de números 09 a 12.

E-mail Spoofing

E-mail spoofing is the forgery of an e-mail header so that

the message appears to have originated from someone or

somewhere other than the actual source. Distributors of spam

often use spoofing in an attempt to get recipients to open,

and possibly even respond to, their solicitations. Spoofing can

be used legitimately. However, spoofing anyone other than

yourself is illegal in some jurisdictions.

E-mail spoofing is possible because Simple Mail Transfer

Protocol (SMTP), the main protocol used in sending e-mail,

does not include an authentication mechanism. Although

an SMTP service extension (specified in IETF RFC 2554)

allows an SMTP client to negotiate a security level with a mail

server, this precaution is not often taken. If the precaution is

not taken, anyone with the requisite knowledge can connect

to the server and use it to send messages. To send spoofed

e-mail, senders insert commands in headers that will alter

message information. It is possible to send a message that

appears to be from anyone, anywhere, saying whatever the

sender wants it to say. Thus, someone could send spoofed

e-mail that appears to be from you with a message that you

didn't write.

Although most spoofed e-mail falls into the nuisance

category and requires little action other than deletion, the

more malicious varieties can cause serious problems and

security risks. For example, spoofed e-mail may purport

to be from someone in a position of authority, asking for

sensitive data, such as passwords, credit card numbers, or

other personal information – any of which can be used for a

variety of criminal purposes. One type of e-mail spoofing, selfsending

spam, involves messages that appear to be both to

and from the recipient.

(http://searchsecurity.techtarget.com/definition/email-spoofing. Adaptado)

An example of sensitive data mentioned in the last paragraph is