Fake online classified adverts are one of the subtle dangers of the internet, as they exclusively rely on social engineering and conning people. Unlike malware or phishing, these attempts can't be effectively blocked by automated software.
The difference between a successful deal and a complete disaster on sites such as Gumtree.com and eBay.co.uk lies in the user's awareness and attention to detail. The user can stay safe at all times by refusing advance payment requests, disclosing only necessary data and evaluating the risks associated with any of their actions.
First of all, the user needs to weigh up what's being asked for against what they receive. Usually, adverts sell goods, products and services in a way that is advantageous to both the seller and the buyer. If the offer is too good to be true, it's most likely a scam. For instance, if a job advert promises the viewer a high income position involving moving money from one account to another but requires no particular qualifications, it should be considered a warning that the funds to be moved probably come from fraud or cybercrime. After all, since the beginning of the worldwide financial crisis, job offerings have dramatically diminished and employers usually ask for over-qualified staff, not the other way around.
The simplest way for users to check whether an advert is legitimate is to research the offering online. If it's a scam, chances are it has already been analysed and detailed by one of the scam watch organisations around the world. This way, the user can get an early warning about the risks they take when signing up for the offering or when they get in direct touch with the seller / advertiser.
Secondly, if the website supports it, investigate the seller's reputation. Some websites log the reputation of specific users to ensure the buyer that they have entered a deal with a trustworthy member of the online community whom other buyers have had a pleasant experience with.
If you suspect you have been the victim of a classified advert scam, there are steps you can take; in the case of an advance-fee scam, notify your bank to block the transaction before clearing or call the police to report the fraud if you sent money via wire transfer.
If you have exposed sensitive information about who you are, where you live and where you work, and you believe you are in any kind of physical danger, you should inform the police.
After you have taken these precautions, contact the online classified website for additional information that might be useful for identifying the scammer and for reporting the fraud. Unfortunately, most online classified websites have strict policies against disclosing users' information to third parties, so further investigation of the incident would require the involvement of law enforcement.
Catalin Cosoi, Chief Security Strategist at Bitdefender