Hey,
My dad is getting these reply messages, such as 'no such recipient', 'auto reply..', 'mail delivery failure', etc.
I don't do IT, but I'm trying to help him the best I can.
The frequency is EXTREMELY high for a personal system behind a router, about 5 e-mails every 1/2 day.
AVG, Spybot, and Malwarebytes' anti-malware all showed up nothing.
Also enabled (it's typically disabled) ZA FW, it did NOT detect any outbound connections from untrusted sources.
Also, appears to be no unknown processes running, though if it's running under an svchost or something then it obviously won't be recognized.
I believe these are ACTUAL mail replies, but I DON'T think they're being sent by his computer. I turned off his computer for a night (usually he leaves it on), and the frequency was left unchanged, the same number of failures or auto-replies were in his inbox when I booted it back up in the morning. This leads me to believe that there's not an actual virus with an SMTP client which is sending e-mails.
I changed his e-mail password, and this appeared to fix it for the day, but the problem came back today. Though I did do this on New Year's Eve so it's very possible there was no correlation between the password change and the disruption of the flow of failures.
This leads me to one of 3 conclusions:
1) There's a virus on his computer which is sending the e-mail password (doubt it's a key logger, it would have to be taking it out of Thunderbird).
2) Spoofs
2a) Somebody's sending e-mails which are spoofed to be FROM him, even though they're not
2b) Somebody's actually sending the e-mail failures (spoofed) TO him.
Note: Never actually got a reply from the recipients, just failures (for variety of reasons including e-mail not existing) or out of office replies.
**
I don't believe the problem is an actual virus on his computer, but I could be wrong. Either way, I am unable to format his system as I don't have the time and he doesn't have the down-time. The system is seemingly snappy and clean, this isn't one of those systems bogged down with malware/spyware.
Any thoughts?
My dad is getting these reply messages, such as 'no such recipient', 'auto reply..', 'mail delivery failure', etc.
I don't do IT, but I'm trying to help him the best I can.
The frequency is EXTREMELY high for a personal system behind a router, about 5 e-mails every 1/2 day.
AVG, Spybot, and Malwarebytes' anti-malware all showed up nothing.
Also enabled (it's typically disabled) ZA FW, it did NOT detect any outbound connections from untrusted sources.
Also, appears to be no unknown processes running, though if it's running under an svchost or something then it obviously won't be recognized.
I believe these are ACTUAL mail replies, but I DON'T think they're being sent by his computer. I turned off his computer for a night (usually he leaves it on), and the frequency was left unchanged, the same number of failures or auto-replies were in his inbox when I booted it back up in the morning. This leads me to believe that there's not an actual virus with an SMTP client which is sending e-mails.
I changed his e-mail password, and this appeared to fix it for the day, but the problem came back today. Though I did do this on New Year's Eve so it's very possible there was no correlation between the password change and the disruption of the flow of failures.
This leads me to one of 3 conclusions:
1) There's a virus on his computer which is sending the e-mail password (doubt it's a key logger, it would have to be taking it out of Thunderbird).
2) Spoofs
2a) Somebody's sending e-mails which are spoofed to be FROM him, even though they're not
2b) Somebody's actually sending the e-mail failures (spoofed) TO him.
Note: Never actually got a reply from the recipients, just failures (for variety of reasons including e-mail not existing) or out of office replies.
**
I don't believe the problem is an actual virus on his computer, but I could be wrong. Either way, I am unable to format his system as I don't have the time and he doesn't have the down-time. The system is seemingly snappy and clean, this isn't one of those systems bogged down with malware/spyware.
Any thoughts?