You're basically looking at the raw data of a certificate signed by a Verisign root, which is not surprising if you're looking at network traces. It doesn't imply anything about the rest of the stream.
"G5" is part of the name of a certificate -
VeriSign Class 3 Primary CA - G5
In this case that's actually the Issuer of the certificate you're actually looking at.
The two long numbers terminated with Z that follow (
150318000000Z150630235959Z) are the Validity period, as per RFC 5280 ss 126.96.36.199:
The certificate validity period is the time interval during which the
CA warrants that it will maintain information about the status of the
certificate. The field is represented as a SEQUENCE of two dates: the
date on which the certificate validity period begins (notBefore) and
the date on which the certificate validity period ends (notAfter).
Both notBefore and notAfter may be encoded as UTCTime or
The Z indicates that they are using UTCTime (RFC 5280 ss 188.8.131.52.1):
The universal time type, UTCTime, is a standard ASN.1 type intended
for representation of dates and time. UTCTime specifies the year
through the two low-order digits and time is specified to the
precision of one minute or one second. UTCTime includes either Z (for
Zulu, or Greenwich Mean Time) or a time differential.
For the purposes of this profile, UTCTime values MUST be expressed in
Greenwich Mean Time (Zulu) and MUST include seconds (i.e., times are
YYMMDDHHMMSSZ), even where the number of seconds is zero.