OneClassClassifier not classifying issue

Hello !
I have the following problem:
 -I am trying to use OneClassClassifier on a anomaly detection problem.
 -My train dataset consits of a binary dataset labeled target(67343 instances) and outlier(0 instances)
 -I am using the default parameters for the one class classifier
 -I am using the supplied test mode for evaluation, my test dataset consists also of a binary dataset labeled target(9746 instances) and outlier(2852 instances)

After the evaluation i obtain the following results:
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=== Evaluation on test set ===
=== Summary ===

Correctly Classified Instances        9746               77.3615 %
Incorrectly Classified Instances      2852               22.6385 %
Kappa statistic                          0    
Mean absolute error                      0.2264
Root mean squared error                  0.4758
Relative absolute error                 99.9964 %
Root relative squared error            100.0015 %
Coverage of cases (0.95 level)          77.3615 %
Mean rel. region size (0.95 level)      50      %
Total Number of Instances            12598    

=== Detailed Accuracy By Class ===

               TP Rate   FP Rate   Precision   Recall  F-Measure   ROC Area   PRC Area  Class
                 0         0          0         0         0          0.5        0.226    outlier
                 1         1          0.774     1         0.872      0.5        0.774    target
Weighted Avg.    0.774     0.774      0.598     0.774     0.675      0.5        0.65

=== Confusion Matrix ===

    a    b   <-- classified as
    0 2852 |    a = outlier
    0 9746 |    b = target
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As it can be seen none of the outlier instances were correctly classified, why is this happening? Am i doing something wrong?

Any help will be greatly appreciated!
Best regards,
AndreiC