1. Introduction

2. Data
2.1. Source pre-selection: WISE×SDSS cross-match
2.2. Parameter space

3. Novelty detection
3.1. Support vector machines
3.2. One-class SVM reformulation
3.3. Classification scheme

4. Results of OCSVM application to AllWISE data
4.1. Anomalies with extremely low W1 − W2 colour: photometric artifacts
4.2. Anomalies with W1-W2>0.8: AGN/quasar candidates

5. Summary and future prospects