Logstash and VirusTotal

Hi All,
i've tried to use Lostash 2.0 with VirusTotal plugin

without any result.
Here my config file snippet:

    virustotal {
            apikey => "myapikey"
            field => [src_ip]
            lookup_type => "url"
            target => "virustotal"

Below the error code

`Exception in filterworker, the pipeline stopped processing new events, please check your filter configuration and restart Logstash. {"exception"=>#<JSON::ParserError: A JSON text must at least contain two octets!>'

JSON::ParserError: A JSON text must at least contain two octets!
     initialize at json/ext/Parser.java:175
            new at json/ext/Parser.java:151
          parse at /opt/logstash/vendor/bundle/jruby/1.9/gems/json-1.8.3-java/lib/json/common.rb:155
         filter at /opt/logstash/vendor/local_gems/0f94f654/logstash-filter-virustotal-0.1.1/lib/logstash/filters/virustotal.rb:53
   multi_filter at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.0.0-java/lib/logstash/filters/base.rb:152
           each at org/jruby/RubyArray.java:1613
   multi_filter at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.0.0-java/lib/logstash/filters/base.rb:149
    filter_func at (eval):1467
   filterworker at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.0.0-java/lib/logstash/pipeline.rb:219
  start_filters at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.0.0-java/lib/logstash/pipeline.rb:154

How can i avoid this error?

Since this error originates in the virustotal plugin perhaps you should contact its author? Reading the plugin's source code it looks like it blindly assumes that it gets a non-empty response from the server but that doesn't seem to hold true in your case.