Entries Tagged "e-mail"

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Brexit Deal Mandates Old Insecure Crypto Algorithms

In what is surely an unthinking cut-and-paste issue, page 921 of the Brexit deal mandates the use of SHA-1 and 1024-bit RSA:

The open standard s/MIME as extension to de facto e-mail standard SMTP will be deployed to encrypt messages containing DNA profile information. The protocol s/MIME (V3) allows signed receipts, security labels, and secure mailing lists… The underlying certificate used by s/MIME mechanism has to be in compliance with X.509 standard…. The processing rules for s/MIME encryption operations… are as follows:

  1. the sequence of the operations is: first encryption and then signing,
  2. the encryption algorithm AES (Advanced Encryption Standard) with 256 bit key length and RSA with 1,024 bit key length shall be applied for symmetric and asymmetric encryption respectively,
  3. the hash algorithm SHA-1 shall be applied.
  4. s/MIME functionality is built into the vast majority of modern e-mail software packages including Outlook, Mozilla Mail as well as Netscape Communicator 4.x and inter-operates among all major e-mail software packages.

And s/MIME? Bleah.

Posted on December 31, 2020 at 6:19 AMView Comments

Detecting Phishing Emails

Research paper: Rick Wash, “How Experts Detect Phishing Scam Emails“:

Abstract: Phishing scam emails are emails that pretend to be something they are not in order to get the recipient of the email to undertake some action they normally would not. While technical protections against phishing reduce the number of phishing emails received, they are not perfect and phishing remains one of the largest sources of security risk in technology and communication systems. To better understand the cognitive process that end users can use to identify phishing messages, I interviewed 21 IT experts about instances where they successfully identified emails as phishing in their own inboxes. IT experts naturally follow a three-stage process for identifying phishing emails. In the first stage, the email recipient tries to make sense of the email, and understand how it relates to other things in their life. As they do this, they notice discrepancies: little things that are “off” about the email. As the recipient notices more discrepancies, they feel a need for an alternative explanation for the email. At some point, some feature of the email — usually, the presence of a link requesting an action — triggers them to recognize that phishing is a possible alternative explanation. At this point, they become suspicious (stage two) and investigate the email by looking for technical details that can conclusively identify the email as phishing. Once they find such information, then they move to stage three and deal with the email by deleting it or reporting it. I discuss ways this process can fail, and implications for improving training of end users about phishing.

Posted on November 6, 2020 at 6:28 AMView Comments

Business Email Compromise (BEC) Criminal Ring

A criminal group called Cosmic Lynx seems to be based in Russia:

Dubbed Cosmic Lynx, the group has carried out more than 200 BEC campaigns since July 2019, according to researchers from the email security firm Agari, particularly targeting senior executives at large organizations and corporations in 46 countries. Cosmic Lynx specializes in topical, tailored scams related to mergers and acquisitions; the group typically requests hundreds of thousands or even millions of dollars as part of its hustles.

[…]

For example, rather than use free accounts, Cosmic Lynx will register strategic domain names for each BEC campaign to create more convincing email accounts. And the group knows how to shield these domains so they’re harder to trace to the true owner. Cosmic Lynx also has a strong understanding of the email authentication protocol DMARC and does reconnaissance to assess its targets’ specific system DMARC policies to most effectively circumvent them.

Cosmic Lynx also drafts unusually clean and credible-looking messages to deceive targets. The group will find a company that is about to complete an acquisition and contact one of its top executives posing as the CEO of the organization being bought. This phony CEO will then involve “external legal counsel” to facilitate the necessary payments. This is where Cosmic Lynx adds a second persona to give the process an air of legitimacy, typically impersonating a real lawyer from a well-regarded law firm in the United Kingdom. The fake lawyer will email the same executive that the “CEO” wrote to, often in a new email thread, and share logistics about completing the transaction. Unlike most BEC campaigns, in which the messages often have grammatical mistakes or awkward wording, Cosmic Lynx messages are almost always clean.

Posted on July 10, 2020 at 6:12 AMView Comments

New iPhone Zero-Day Discovered

Last year, ZecOps discovered two iPhone zero-day exploits. They will be patched in the next iOS release:

Avraham declined to disclose many details about who the targets were, and did not say whether they lost any data as a result of the attacks, but said “we were a bit surprised about who was targeted.” He said some of the targets were an executive from a telephone carrier in Japan, a “VIP” from Germany, managed security service providers from Saudi Arabia and Israel, people who work for a Fortune 500 company in North America, and an executive from a Swiss company.

[…]

On the other hand, this is not as polished a hack as others, as it relies on sending an oversized email, which may get blocked by certain email providers. Moreover, Avraham said it only works on the default Apple Mail app, and not on Gmail or Outlook, for example.

Posted on April 22, 2020 at 9:12 AMView Comments

Deep Learning to Find Malicious Email Attachments

Google presented its system of using deep-learning techniques to identify malicious email attachments:

At the RSA security conference in San Francisco on Tuesday, Google’s security and anti-abuse research lead Elie Bursztein will present findings on how the new deep-learning scanner for documents is faring against the 300 billion attachments it has to process each week. It’s challenging to tell the difference between legitimate documents in all their infinite variations and those that have specifically been manipulated to conceal something dangerous. Google says that 63 percent of the malicious documents it blocks each day are different than the ones its systems flagged the day before. But this is exactly the type of pattern-recognition problem where deep learning can be helpful.

[…]

The document analyzer looks for common red flags, probes files if they have components that may have been purposefully obfuscated, and does other checks like examining macros­ — the tool in Microsoft Word documents that chains commands together in a series and is often used in attacks. The volume of malicious documents that attackers send out varies widely day to day. Bursztein says that since its deployment, the document scanner has been particularly good at flagging suspicious documents sent in bursts by malicious botnets or through other mass distribution methods. He was also surprised to discover how effective the scanner is at analyzing Microsoft Excel documents, a complicated file format that can be difficult to assess.

This is the sort of thing that’s pretty well optimized for machine-learning techniques.

Posted on February 28, 2020 at 11:57 AMView Comments

Companies that Scrape Your Email

Motherboard has a long article on apps — Edison, Slice, and Cleanfox — that spy on your email by scraping your screen, and then sell that information to others:

Some of the companies listed in the J.P. Morgan document sell data sourced from “personal inboxes,” the document adds. A spokesperson for J.P. Morgan Research, the part of the company that created the document, told Motherboard that the research “is intended for institutional clients.”

That document describes Edison as providing “consumer purchase metrics including brand loyalty, wallet share, purchase preferences, etc.” The document adds that the “source” of the data is the “Edison Email App.”

[…]

A dataset obtained by Motherboard shows what some of the information pulled from free email app users’ inboxes looks like. A spreadsheet containing data from Rakuten’s Slice, an app that scrapes a user’s inbox so they can better track packages or get their money back once a product goes down in price, contains the item that an app user bought from a specific brand, what they paid, and an unique identification code for each buyer.

Posted on February 12, 2020 at 10:26 AMView Comments

US Journalist Detained When Returning to US

Pretty horrible story of a US journalist who had his computer and phone searched at the border when returning to the US from Mexico.

After I gave him the password to my iPhone, Moncivias spent three hours reviewing hundreds of photos and videos and emails and calls and texts, including encrypted messages on WhatsApp, Signal, and Telegram. It was the digital equivalent of tossing someone’s house: opening cabinets, pulling out drawers, and overturning furniture in hopes of finding something — anything — illegal. He read my communications with friends, family, and loved ones. He went through my correspondence with colleagues, editors, and sources. He asked about the identities of people who have worked with me in war zones. He also went through my personal photos, which I resented. Consider everything on your phone right now. Nothing on mine was spared.

Pomeroy, meanwhile, searched my laptop. He browsed my emails and my internet history. He looked through financial spreadsheets and property records and business correspondence. He was able to see all the same photos and videos as Moncivias and then some, including photos I thought I had deleted.

The EFF has extensive information and advice about device searches at the US border, including a travel guide:

If you are a U.S. citizen, border agents cannot stop you from entering the country, even if you refuse to unlock your device, provide your device password, or disclose your social media information. However, agents may escalate the encounter if you refuse. For example, agents may seize your devices, ask you intrusive questions, search your bags more intensively, or increase by many hours the length of detention. If you are a lawful permanent resident, agents may raise complicated questions about your continued status as a resident. If you are a foreign visitor, agents may deny you entry.

The most important piece of advice is to think about this all beforehand, and plan accordingly.

Posted on July 4, 2019 at 6:38 AMView Comments

Using Gmail "Dot Addresses" to Commit Fraud

In Gmail addresses, the dots don’t matter. The account “bruceschneier@gmail.com” maps to the exact same address as “bruce.schneier@gmail.com” and “b.r.u.c.e.schneier@gmail.com” — and so on. (Note: I own none of those addresses, if they are actually valid.)

This fact can be used to commit fraud:

Recently, we observed a group of BEC actors make extensive use of Gmail dot accounts to commit a large and diverse amount of fraud. Since early 2018, this group has used this fairly simple tactic to facilitate the following fraudulent activities:

  • Submit 48 credit card applications at four US-based financial institutions, resulting in the approval of at least $65,000 in fraudulent credit
  • Register for 14 trial accounts with a commercial sales leads service to collect targeting data for BEC attacks
  • File 13 fraudulent tax returns with an online tax filing service
  • Submit 12 change of address requests with the US Postal Service
  • Submit 11 fraudulent Social Security benefit applications
  • Apply for unemployment benefits under nine identities in a large US state
  • Submit applications for FEMA disaster assistance under three identities

In each case, the scammers created multiple accounts on each website within a short period of time, modifying the placement of periods in the email address for each account. Each of these accounts is associated with a different stolen identity, but all email from these services are received by the same Gmail account. Thus, the group is able to centralize and organize their fraudulent activity around a small set of email accounts, thereby increasing productivity and making it easier to continue their fraudulent behavior.

This isn’t a new trick. It has been previously documented as a way to trick Netflix users.

News article.

Slashdot thread.

Posted on February 6, 2019 at 10:24 AMView Comments

Real-Time Attacks Against Two-Factor Authentication

Attackers are targeting two-factor authentication systems:

Attackers working on behalf of the Iranian government collected detailed information on targets and used that knowledge to write spear-phishing emails that were tailored to the targets’ level of operational security, researchers with security firm Certfa Lab said in a blog post. The emails contained a hidden image that alerted the attackers in real time when targets viewed the messages. When targets entered passwords into a fake Gmail or Yahoo security page, the attackers would almost simultaneously enter the credentials into a real login page. In the event targets’ accounts were protected by 2fa, the attackers redirected targets to a new page that requested a one-time password.

This isn’t new. I wrote about this exact attack in 2005 and 2009.

Posted on December 14, 2018 at 10:02 AMView Comments

Facebook Is Using Your Two-Factor Authentication Phone Number to Target Advertising

From Kashmir Hill:

Facebook is not content to use the contact information you willingly put into your Facebook profile for advertising. It is also using contact information you handed over for security purposes and contact information you didn’t hand over at all, but that was collected from other people’s contact books, a hidden layer of details Facebook has about you that I’ve come to call “shadow contact information.” I managed to place an ad in front of Alan Mislove by targeting his shadow profile. This means that the junk email address that you hand over for discounts or for shady online shopping is likely associated with your account and being used to target you with ads.

Here’s the research paper. Hill again:

They found that when a user gives Facebook a phone number for two-factor authentication or in order to receive alerts about new log-ins to a user’s account, that phone number became targetable by an advertiser within a couple of weeks. So users who want their accounts to be more secure are forced to make a privacy trade-off and allow advertisers to more easily find them on the social network.

Posted on October 2, 2018 at 5:53 AMView Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.