<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
  </head>
  <body>
    <p>And then there's this change in packets:</p>
    <pre><blockquote type="cite"><span class="raw_line_err" style="box-sizing: border-box; font-family: Verdana, Arial, Helvetica, sans-serif; white-space: nowrap; color: rgb(255, 0, 0); font-size: 12px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;">2020-04-30 12:42:16 EDT:<span> </span><b style="box-sizing: border-box; font-weight: 700;"><a href="https://aprs.fi/?c=raw&limit=&call=UNDEFINED" style="box-sizing: border-box; background-color: transparent; color: rgb(0, 0, 255); text-decoration: none; cursor: pointer; outline-style: none;">UNDEFINED</a></b>>APRS,TCPIP*,qAC,<a class="moz-txt-link-abbreviated" href="mailto:T2DENMARK:@301642z193.83N/0986.32Euundefined/V1.0">T2DENMARK:@301642z193.83N/0986.32Euundefined/V1.0</a><span> </span><b style="box-sizing: border-box; font-weight: 700;">[Invalid uncompressed location]</b></span>
<span class="raw_line_err" style="box-sizing: border-box; font-family: Verdana, Arial, Helvetica, sans-serif; white-space: nowrap; color: rgb(255, 0, 0); font-size: 12px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;">2020-04-30 12:42:17 EDT:<span> </span><b style="box-sizing: border-box; font-weight: 700;"><a href="https://aprs.fi/?c=raw&limit=&call=undefined" style="box-sizing: border-box; background-color: transparent; color: rgb(0, 0, 255); text-decoration: none; cursor: pointer; outline-style: none;">undefined</a></b>>APRS,TCPIP*,qAS,<a href="https://aprs.fi/?c=raw&limit=&call=UNDEFINED" style="box-sizing: border-box; background-color: transparent; color: rgb(0, 0, 255); text-decoration: none; cursor: pointer; outline-style: none;">UNDEFINED</a>:@301642z2056.57N/09725.17Euundefined/V1.0<span> </span><b style="box-sizing: border-box; font-weight: 700;">[Rate limited (< 5 sec)]</b></span>
<span class="raw_line_err" style="box-sizing: border-box; font-family: Verdana, Arial, Helvetica, sans-serif; white-space: nowrap; color: rgb(255, 0, 0); font-size: 12px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;">2020-04-30 12:42:17 EDT:<span> </span><b style="box-sizing: border-box; font-weight: 700;"><a href="https://aprs.fi/?c=raw&limit=&call=undefined" style="box-sizing: border-box; background-color: transparent; color: rgb(0, 0, 255); text-decoration: none; cursor: pointer; outline-style: none;">undefined</a></b>>APRS,TCPIP*,qAS,<a href="https://aprs.fi/?c=raw&limit=&call=UNDEFINED" style="box-sizing: border-box; background-color: transparent; color: rgb(0, 0, 255); text-decoration: none; cursor: pointer; outline-style: none;">UNDEFINED</a>:@301642z3143.75N/11641.88Euundefined/V1.0<span> </span><b style="box-sizing: border-box; font-weight: 700;">[Rate limited (< 5 sec)]</b></span>
<span class="raw_line_err" style="box-sizing: border-box; font-family: Verdana, Arial, Helvetica, sans-serif; white-space: nowrap; color: rgb(255, 0, 0); font-size: 12px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial;">2020-04-30 12:42:18 EDT:<span> </span><b style="box-sizing: border-box; font-weight: 700;"><a href="https://aprs.fi/?c=raw&limit=&call=UNDEFINED" style="box-sizing: border-box; background-color: transparent; color: rgb(0, 0, 255); text-decoration: none; cursor: pointer; outline-style: none;">UNDEFINED</a></b>>APRS,TCPIP*,qAC,<a class="moz-txt-link-abbreviated" href="mailto:T2FRANCE:@301642z1916.39N/09937.08Euundefined/V1.0">T2FRANCE:@301642z1916.39N/09937.08Euundefined/V1.0</a><span> </span><b style="box-sizing: border-box; font-weight: 700;">[Rate limited (< 5 sec)]</b></span></blockquote>
</pre>
    <div class="moz-signature">And with that V1.0 hanging out in the
      comment, it just smells like a new client being authored.</div>
    <div class="moz-signature"><br>
    </div>
    <div class="moz-signature">Lynn (D) - KJ4ERJ - Author of APRSISCE
      for Windows Mobile and Win32
      <br>
      <br>
    </div>
    <div class="moz-cite-prefix">On 4/30/2020 12:45 PM, Lynn W
      Deffenbaugh (Mr) wrote:<br>
    </div>
    <blockquote type="cite"
      cite="mid:853af3e1-4c0f-5aa5-ca5f-9e39baf48351@arrl.net">
      <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
      <div class="moz-cite-prefix">There are many valid APRS stations
        that use so-called tactical calls that look just like this one,
        so any attempt at automatic filtering would not be a good idea.</div>
      <div class="moz-cite-prefix"><br>
      </div>
      <div class="moz-cite-prefix">I'm suspecting it may be one new
        software implementation that is executing on several devices in
        different locations.  But that's just a guess.  I didn't look at
        the servers it was coming through, but that can also be
        explained by a novice coder that is resolving a round-robin DNS,
        connecting to the server, logging in, sending the packet and
        dropping the connection rather than keeping it open.</div>
      <div class="moz-cite-prefix"><br>
      </div>
      <div class="moz-cite-prefix">I think if it were an actual DOS
        attempt, the tracks wouldn't be following roads if you ignore
        the physics-defying jumps.</div>
      <div class="moz-cite-prefix"><br>
      </div>
      Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and
      Win32 <br>
      <div class="moz-signature"><br>
      </div>
      <div class="moz-cite-prefix"><br>
      </div>
      <div class="moz-cite-prefix">On 4/30/2020 11:55 AM, spam8mybrain
        via aprssig wrote:<br>
      </div>
      <blockquote type="cite"
        cite="mid:rx15et94h0on1b92w3tfi9av.1588262118599@email.android.com">
        <meta http-equiv="Content-Type" content="text/html;
          charset=UTF-8">
        Is it coming from a single client IP address, or do they have a
        botnet driving this?
        <div><br>
        </div>
        <div>Since UNDEFINED is not a valid callsign, can the backbone
          servers blacklist this?</div>
        <div><br>
        </div>
        <div>Perhaps the servers need a patch so that the callsign-SSID
          has to look semi-legitimate (digits and letters, part
          preceding a hyphen limited to 6 or 7 characters, etc.). Of
          course, that level of hardening would be easy for the evil one
          to work around by just forging a legitimate callsign. But
          let's not document it, since legitimate users would never be
          hindered by the constraint.</div>
        <div><br>
        </div>
        <div>Andrew, KA2DDO</div>
        <div>author of YAAC</div>
        <div><br>
        </div>
        <br>
        <br>
        -------- Original message --------<br>
        From: John Langner WB2OSZ <a class="moz-txt-link-rfc2396E"
          href="mailto:wb2osz@comcast.net" moz-do-not-send="true"><wb2osz@comcast.net></a>
        <br>
        Date: 4/30/20 10:49 (GMT-05:00) <br>
        To: <a class="moz-txt-link-abbreviated"
          href="mailto:aprssig@lists.tapr.org" moz-do-not-send="true">aprssig@lists.tapr.org</a>
        <br>
        Subject: [aprssig] UNDEFINED? <br>
        <br>
        This looks like a deliberate attack, not an innocent accidental<br>
        misconfiguration.<br>
        <br>
        It appears to be scanning thru a large number of T2 servers,
        around the<br>
        world. The location is bouncing all over the place, perhaps to
        thwart<br>
        duplicate removal and fill up the database.<br>
        <br>
        <br>
        At  <a class="moz-txt-link-freetext"
          href="http://ontario.aprs2.net:14501/" moz-do-not-send="true">http://ontario.aprs2.net:14501/</a>  
        we find:<br>
        <br>
        <br>
        187.210.189.241 UNDEFINED true gpserver  corget.cn No filter<br>
        set 0d1h0m4.17s 121 2,402 7,676 184,425 21 512<br>
        0d0h0m4.249s<br>
        <br>
        2400 packets per hour to the Ontario server alone.  <br>
        <br>
        This might be an attempt at a denial of service attack.<br>
        <br>
        <br>
        <br>
        <br>
        _______________________________________________<br>
        aprssig mailing list<br>
        <a class="moz-txt-link-abbreviated"
          href="mailto:aprssig@lists.tapr.org" moz-do-not-send="true">aprssig@lists.tapr.org</a><br>
        <a class="moz-txt-link-freetext"
          href="http://lists.tapr.org/mailman/listinfo/aprssig_lists.tapr.org"
          moz-do-not-send="true">http://lists.tapr.org/mailman/listinfo/aprssig_lists.tapr.org</a><br>
        <br>
        <fieldset class="mimeAttachmentHeader"></fieldset>
        <pre class="moz-quote-pre" wrap="">_______________________________________________
aprssig mailing list
<a class="moz-txt-link-abbreviated" href="mailto:aprssig@lists.tapr.org" moz-do-not-send="true">aprssig@lists.tapr.org</a>
<a class="moz-txt-link-freetext" href="http://lists.tapr.org/mailman/listinfo/aprssig_lists.tapr.org" moz-do-not-send="true">http://lists.tapr.org/mailman/listinfo/aprssig_lists.tapr.org</a>
</pre>
      </blockquote>
      <p><br>
      </p>
      <br>
      <fieldset class="mimeAttachmentHeader"></fieldset>
      <pre class="moz-quote-pre" wrap="">_______________________________________________
aprssig mailing list
<a class="moz-txt-link-abbreviated" href="mailto:aprssig@lists.tapr.org">aprssig@lists.tapr.org</a>
<a class="moz-txt-link-freetext" href="http://lists.tapr.org/mailman/listinfo/aprssig_lists.tapr.org">http://lists.tapr.org/mailman/listinfo/aprssig_lists.tapr.org</a>
</pre>
    </blockquote>
  </body>
</html>