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Robocall Results from a Telephony Honeypot

A group of researchers set up a telephony honeypot and tracked robocall behavior:

NCSU researchers said they ran 66,606 telephone lines between March 2019 and January 2020, during which time they said to have received 1,481,201 unsolicited calls — even if they never made their phone numbers public via any source.

The research team said they usually received an unsolicited call every 8.42 days, but most of the robocall traffic came in sudden surges they called “storms” that happened at regular intervals, suggesting that robocallers operated using a tactic of short-burst and well-organized campaigns.

In total, the NCSU team said it tracked 650 storms over 11 months, with most storms being of the same size.

Research paper. USENIX talk. Slashdot thread.

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Encryption Facebook Intelwars machinelearning Metadata securityengineering

Facebook Announces Messenger Security Features that Don’t Compromise Privacy

Note that this is “announced,” so we don’t know when it’s actually going to be implemented.

Facebook today announced new features for Messenger that will alert you when messages appear to come from financial scammers or potential child abusers, displaying warnings in the Messenger app that provide tips and suggest you block the offenders. The feature, which Facebook started rolling out on Android in March and is now bringing to iOS, uses machine learning analysis of communications across Facebook Messenger’s billion-plus users to identify shady behaviors. But crucially, Facebook says that the detection will occur only based on metadata­ — not analysis of the content of messages­ — so that it doesn’t undermine the end-to-end encryption that Messenger offers in its Secret Conversations feature. Facebook has said it will eventually roll out that end-to-end encryption to all Messenger chats by default.

That default Messenger encryption will take years to implement.

More:

Facebook hasn’t revealed many details about how its machine-learning abuse detection tricks will work. But a Facebook spokesperson tells WIRED the detection mechanisms are based on metadata alone: who is talking to whom, when they send messages, with what frequency, and other attributes of the relevant accounts — essentially everything other than the content of communications, which Facebook’s servers can’t access when those messages are encrypted. “We can get pretty good signals that we can develop through machine learning models, which will obviously improve over time,” a Facebook spokesperson told WIRED in a phone call. They declined to share more details in part because the company says it doesn’t want to inadvertently help bad actors circumvent its safeguards.

The company’s blog post offers the example of an adult sending messages or friend requests to a large number of minors as one case where its behavioral detection mechanisms can spot a likely abuser. In other cases, Facebook says, it will weigh a lack of connections between two people’s social graphs — a sign that they don’t know each other — or consider previous instances where users reported or blocked a someone as a clue that they’re up to something shady.

One screenshot from Facebook, for instance, shows an alert that asks if a message recipient knows a potential scammer. If they say no, the alert suggests blocking the sender, and offers tips about never sending money to a stranger. In another example, the app detects that someone is using a name and profile photo to impersonate the recipient’s friend. An alert then shows the impersonator’s and real friend’s profiles side-by-side, suggesting that the user block the fraudster.

Details from Facebook

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intelligence Intelwars Metadata nationalsecuritypolicy NSA Phones

Newly Declassified Study Demonstrates Uselessness of NSA’s Phone Metadata Program

The New York Times is reporting on the NSA’s phone metadata program, which the NSA shut down last year:

A National Security Agency system that analyzed logs of Americans’ domestic phone calls and text messages cost $100 million from 2015 to 2019, but yielded only a single significant investigation, according to a newly declassified study.

Moreover, only twice during that four-year period did the program generate unique information that the F.B.I. did not already possess, said the study, which was produced by the Privacy and Civil Liberties Oversight Board and briefed to Congress on Tuesday.

[…]

The privacy board, working with the intelligence community, got several additional salient facts declassified as part of the rollout of its report. Among them, it officially disclosed that the system has gained access to Americans’ cellphone records, not just logs of landline phone calls.

It also disclosed that in the four years the Freedom Act system was operational, the National Security Agency produced 15 intelligence reports derived from it. The other 13, however, contained information the F.B.I. had already collected through other means, like ordinary subpoenas to telephone companies.

The report cited two investigations in which the National Security Agency produced reports derived from the program: its analysis of the Pulse nightclub mass shooting in Orlando, Fla., in June 2016 and of the November 2016 attack at Ohio State University by a man who drove his car into people and slashed at them with a machete. But it did not say whether the investigations into either of those attacks were connected to the two intelligence reports that provided unique information not already in the possession of the F.B.I.

This program is legal due to the USA FREEDOM Act, which expires on March 15. Congress is currently debating whether to extend the authority, even though the NSA says it’s not using it now.

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