U.S. federal agencies are warning citizens anxious to donate money for those victimized by Hurricane Harvey to be especially wary of scam artists. In years past we’ve seen shameless fraudsters stand up fake charities and other bogus relief efforts in a bid to capitalize on public concern over an ongoing disaster. Here are some tips to help ensure sure your aid dollars go directly to those most in need.

The Federal Trade Commission (FTC) issued an alert Monday urging consumers to be on the lookout for a potential surge in charity scams. The FTC advises those who wish to donate to stick to charities they know, and to be on the lookout for charities or relief Web sites that seem to have sprung up overnight in response to current events (such as houstonfloodrelief.net, registered on Aug. 28, 2017). Sometimes these sites are set up by well-meaning people with the best of intentions (however misguided), but it’s best not to take a chance.

The FTC also warns consumers not to assume that a charity message posted on social media is a legitimate, and urges folks to research the organization before donating by visiting charity evaluation sites such as Charity Navigator, Charity Watch, GuideStar, or the Better Business Bureau’s Wise Giving Alliance. The agency also reminds people who wish to donate via text message to confirm the number with the source before you donate.

From the US Computer Emergency Readiness Team (US-CERT) comes a reminder that malware purveyors frequently use natural disasters and other breaking news items of broad interest to trick people into clicking on malicious links or opening booby-trapped email attachments.

If anyone spots additional recently-registered Harvey-themed relief domains, please drop a note in the comments below.

Update, 11:42 p.m. ET: A reader pointed out a newly-registered domain — harveyfloodrelief[dot]org — that is currently requesting PayPal donations on behalf of Harvey victims.

A half dozen technology and security companies — some of them competitors — issued the exact same press release today. This unusual level of cross-industry collaboration caps a successful effort to dismantle ‘WireX,’ an extraordinary new crime machine comprising tens of thousands of hacked Android mobile devices that was used this month to launch a series of massive cyber attacks.

Experts involved in the takedown warn that WireX marks the emergence of a new class of attack tools that are more challenging to defend against and thus require broader industry cooperation to defeat.

News of WireX’s emergence first surfaced August 2, 2017, when a modest collection of hacked Android devices was first spotted conducting some fairly small online attacks. Less than two weeks later, however, the number of infected Android devices enslaved by WireX had ballooned to the tens of thousands.

More worrisome was that those in control of the botnet were now wielding it to take down several large websites in the hospitality industry — pelting the targeted sites with so much junk traffic that the sites were no longer able to accommodate legitimate visitors.

Experts tracking the attacks soon zeroed in on the malware that powers WireX: Approximately 300 different mobile apps scattered across Google‘s Play store that were mimicking seemingly innocuous programs, including video players, ringtones or simple tools such as file managers.

“We identified approximately 300 apps associated with the issue, blocked them from the Play Store, and we’re in the process of removing them from all affected devices,” Google said in a written statement. “The researchers’ findings, combined with our own analysis, have enabled us to better protect Android users, everywhere.”

Perhaps to avoid raising suspicion, the tainted Play store applications all performed their basic stated functions. But those apps also bundled a small program that would launch quietly in the background and cause the infected mobile device to surreptitiously connect to an Internet server used by the malware’s creators to control the entire network of hacked devices. From there, the infected mobile device would await commands from the control server regarding which Websites to attack and how.

Experts involved in the takedown say it’s not clear exactly how many Android devices may have been infected with WireX, in part because only a fraction of the overall infected systems were able to attack a target at any given time. Devices that were powered off would not attack, but those that were turned on with the device’s screen locked could still carry on attacks in the background, they found.

“I know in the cases where we pulled data out of our platform for the people being targeted we saw 130,000 to 160,000 (unique Internet addresses) involved in the attack,” said Chad Seaman, a senior engineer at Akamai, a company that specializes in helping firms weather large DDoS attacks (Akamai protected KrebsOnSecurity from hundreds of attacks prior to the large Mirai assault last year).

The identical press release that Akamai and other firms involved in the WireX takedown agreed to publish says the botnet infected a minimum of 70,000 Android systems, but Seaman says that figure is conservative.

“Seventy thousand was a safe bet because this botnet makes it so that if you’re driving down the highway and your phone is busy attacking some website, there’s a chance your device could show up in the attack logs with three or four or even five different Internet addresses,” Seaman said in an interview with KrebsOnSecurity. “We saw attacks coming from infected devices in over 100 countries. It was coming from everywhere.”

BUILDING ON MIRAI

Security experts from Akamai and other companies that participated in the WireX takedown say the basis for their collaboration was forged in the monstrous and unprecedented distributed denial-of-service (DDoS) attacks launched last year by Mirai, a malware strain that seeks out poorly-secured “Internet of things” (IoT) devices such as security cameras, digital video recorders and Internet routers.

The first and largest of the Mirai botnets was used in a giant attack last September that knocked this Web site offline for several days. Just a few days after that — when the source code that powers Mirai was published online for all the world to see and use — dozens of copycat Mirai botnets emerged. Several of those botnets were used to conduct massive DDoS attacks against a variety of targets, leading to widespread Internet outages for many top Internet destinations.

Allison Nixon, director of security research at New York City-based security firm Flashpoint, said the Mirai attacks were a wake-up call for the security industry and a rallying cry for more collaboration.

“When those really large Mirai DDoS botnets started showing up and taking down massive pieces of Internet infrastructure, that caused massive interruptions in service for people that normally don’t deal with DDoS attacks,” Nixon said. “It sparked a lot of collaboration. Different players in the industry started to take notice, and a bunch of us realized that we needed to deal with this thing because if we didn’t it would just keep getting bigger and rampaging around.”

Mirai was notable not only for the unprecedented size of the attacks it could launch but also for its ability to spread rapidly to new machines. But for all its sheer firepower, Mirai is not a particularly sophisticated attack platform. Well, not in comparison to WireX, that is.

CLICK-FRAUD ORIGINS

According to the group’s research, the WireX botnet likely began its existence as a distributed method for conducting “click fraud,” a pernicious form of online advertising fraud that will cost publishers and businesses an estimated $16 billion this year, according to recent estimates. Multiple antivirus tools currently detect the WireX malware as a known click fraud malware variant.

The researchers believe that at some point the click-fraud botnet was repurposed to conduct DDoS attacks. While DDoS botnets powered by Android devices are extremely unusual (if not unprecedented at this scale), it is the botnet’s ability to generate what appears to be regular Internet traffic from mobile browsers that strikes fear in the heart of experts who specialize in defending companies from large-scale DDoS attacks.

DDoS defenders often rely on developing custom “filters” or “signatures” that can help them separate DDoS attack traffic from legitimate Web browser traffic destined for a targeted site. But experts say WireX has the capability to make that process much harder.

That’s because WireX includes its own so-called “headless” Web browser that can do everything a real, user-driven browser can do, except without actually displaying the browser to the user of the infected system.

Also, Wirex can encrypt the attack traffic using SSL — the same technology that typically protects the security of a browser session when an Android user visits a Web site which requires the submission of sensitive data. This adds a layer of obfuscation to the attack traffic, because the defender needs to decrypt incoming data packets before being able to tell whether the traffic inside matches a malicious attack traffic signature.

Translation: It can be far more difficult and time-consuming than usual for defenders to tell WireX traffic apart from clicks generated by legitimate Internet users trying to browse to a targeted site.

“These are pretty miserable and painful attacks to mitigate, and it was these kinds of advanced functionalities that made this threat stick out like a sore thumb,” Akamai’s Seaman said.

NOWHERE TO HIDE

Traditionally, many companies that found themselves on the receiving end of a large DDoS attack sought to conceal this fact from the public — perhaps out of fear that customers or users might conclude the attack succeeded because of some security failure on the part of the victim.

But the stigma associated with being hit with a large DDoS is starting to fade, Flashpoint’s Nixon said, if for no other reason than it is becoming far more difficult for victims to conceal such attacks from public knowledge.

“Many companies, including Flashpoint, have built out different capabilities in order to see when a third party is being DDoS’d,” Nixon said. “Even though I work at a company that doesn’t do DDoS mitigation, we can still get visibility when a third-party is getting attacked. Also, network operators and ISPs have a strong interest in not having their networks abused for DDoS, and many of them have built capabilities to know when their networks are passing DDoS traffic.”

Just as multiple nation states now employ a variety of techniques and technologies to keep tabs on nation states that might conduct underground tests of highly destructive nuclear weapons, a great deal more organizations are now actively looking for signs of large-scale DDoS attacks, Seaman added.

“The people operating those satellites and seismograph sensors to detect nuclear [detonations] can tell you how big it was and maybe what kind of bomb it was, but they probably won’t be able to tell you right away who launched it,” he said. “It’s only when we take many of these reports together in the aggregate that we can get a much better sense of what’s really going on. It’s a good example of none of us being as smart as all of us.”

According to the WireX industry consortium, the smartest step that organizations can take when under a DDoS attack is to talk to their security vendor(s) and make it clear that they are open to sharing detailed metrics related to the attack.

“With this information, those of us who are empowered to dismantle these schemes can learn much more about them than would otherwise be possible,” the report notes. “There is no shame in asking for help. Not only is there no shame, but in most cases it is impossible to hide the fact that you are under a DDoS attack. A number of research efforts have the ability to detect the existence of DDoS attacks happening globally against third parties no matter how much those parties want to keep the issue quiet. There are few benefits to being secretive and numerous benefits to being forthcoming.”

Identical copies of the WireX report and Appendix are available at the following links:

Flashpoint

Akamai

Cloudflare

RiskIQ

More online services than ever now offer two-step authentication — requiring customers to complete a login using their phone or other mobile device after supplying a username and password. But with so many services relying on your mobile for that second factor, there has never been more riding on the security of your mobile account. Below are some tips to ensure your mobile device (or, more specifically, your mobile carrier) isn’t the weakest link in your security chain.

For reasons explored more in The Value of a Hacked Email Account, many people become so preoccupied with securing online access to their financial accounts that they overlook or forget the fact that all of those precautions may be moot if hackers can access your email inbox. From that 2013 piece:

“Sign up with any service online, and it will almost certainly require you to supply an email address. In nearly all cases, the person who is in control of that address can reset the password of any associated services or accounts –merely by requesting a password reset email.”

Many webmail providers now encourage users to take advantage of two-step (a.k.a. “two factor”) authentication methods in addition to passwords for securing access to email. This usually involves the user adding a mobile phone number to their account that gets sent a one-time code that needs to be entered after supplying the account password. The idea here is that even if thieves somehow manage to phish or otherwise glean your account password, they still need access to your phone to discover the one-time code.

Depending on how you’ve set up two-step authentication, however, this may be far from airtight security. What’s more, not all two-step authentication methods are equally secure. Probably the most common form of secondary authentication — a one-time code sent to your mobile device via SMS/text message — is also the least secure.

That’s because thieves who manage to phish or otherwise filch your password can then simply ring your mobile provider pretending to be you, claiming that your phone is lost and that you need to activate a new phone and corresponding new SIM card. Or, they convince a gullible or inexperienced customer support rep to temporarily forward all of your calls and texts to a different number (this happened to me in 2013).

A harrowing story in The New York Times last week showcased several such hacks against Bitcoin enthusiasts, but in truth these types of social engineering attacks have been going on for years.

True, not everyone will attract the kind of interest from cybercrooks as someone holding large amounts of a non-repudiable virtual currency. But it’s still a good idea to take a few minutes and check whether some of the services you use that offer two-step authentication might offer an app-based method — such as Google Authenticator or Authy — as opposed to a text-based method.

By the way, I’m not the only one bugging people to move away from texting for codes: The National Institute of Standards and Technology (NIST) recently issued new proposed digital authentication guidelines urging organizations to favor other forms of two-factor — such as time-base one-time passwords generated by mobile apps — over text messaging.

Fortunately, some of the more popular online services offer multiple options for two-step authentication, although many of those that offer alternatives to texting one-time codes still steer users toward this option. I took stock of my own exposure to text-based two-step authentication and found three services I rely upon daily for my work still had the SMS option selected when a more secure app-based option was available.

Take a moment to review the authentication options available for the services you use on a regular basis. To do this, head on over to twofactorauth.org. A simple search for “Facebook,” for example, shows that the social networking site offers secondary authentication options via SMS, hardware token (such as a physical USB security key) and software token (Google Authenticator, e.g.).

In the case of Facebook, if you previously received one-time tokens via SMS, you may have to temporarily disable two-step authentication via text message before enabling the security key and software token approaches.

Also, some people (present company included) need extra security and may be willing to put up with additional minor inconveniences in exchange for added peace of mind that thieves aren’t going to just waltz in and steal everything. This is particularly true for people with serious assets tied up in online sites and services that may not offer more robust authentication options.

This piece over at Techcrunch last week tells the story of another Bitcoin enthusiast who took some pretty extreme measures after someone tricked his mobile provider into switching his account to a new phone. Like requesting that the provider lock your phone’s SIM card to your device and prevent the phone from being used with another SIM card (the downside of this is if you really do lose your phone it could be much more complicated with this option turned on).

The story also recommends calling your telecommunications provider and asking them to set a passcode or PIN on your account that needs to be supplied before a customer service representative will discuss the account details.

“Make sure it applies to ALL account changes,” the Techcrunch pieces advises. “Make sure it applies to all numbers on the account. Ask them what happens if you forget the passcode. Ask them what happens if you lose that too.”

I should note that just because SMS is less secure than other forms of two-step authentication, that should not disqualify it as a worthwhile security step when more secure alternatives are unavailable. Any form of two-factor authentication is better than relying solely on usernames and passwords.

Some online services allow people to receive one-time codes via an automated phonecall. I hope it goes without saying this, but this method also is vulnerable to an attacker tricking a customer support person at your mobile provider into doing something they shouldn’t. Read the penultimate update to this 2012 blog post about how the CEO of Cloudflare had his account hacked after someone social engineered an AT&T representative into forwarding his second factor by automated phone call to a number the attackers controlled.

Finally, be judicious about what you install on your mobile device, and spend a few minutes researching the reputation and longevity of any app you wish to install before you install it. Also, pay close attention the permissions being requested by apps that you install: A mobile device compromised by mobile malware may not be the most reliable or secure second factor.

An October 2015 piece published here about the potential dangers of tossing out or posting online your airline boarding pass remains one of the most-read stories on this site. One reason may be that the advice remains timely and relevant: A talk recently given at a Czech security conference advances that research and offers several reminders of how being careless with your boarding pass could jeopardize your privacy or even cause trip disruptions down the road.

In What’s In a Boarding Pass Barcode? A Lot, KrebsOnSecurity told the story of a reader whose friend posted a picture of a boarding pass on Facebook. The reader was able to use the airline’s Web site combined with data printed on the boarding pass to discover additional information about his friend. That data included details of future travel, the ability to alter or cancel upcoming flights, and a key component need to access the traveler’s frequent flyer account.

More recently, security researcher Michal Špaček gave a talk at a conference in the Czech Republic in which he explained how a few details gleaned from a picture of a friend’s boarding pass posted online give him the ability to view passport information on his friend via the airline’s Web site, and to change the password for another friend’s United Airlines frequent flyer account.

Working from a British Airways boarding pass that a friend posted to Instagram, Špaček found he could log in to the airline’s passenger reservations page using the six-digit booking code (a.k.a. PNR or passenger name record) and the last name of the passenger (both are displayed on the front of the BA boarding pass).

Once inside his friend’s account, Špaček saw he could cancel future flights, and view or edit his friend’s passport number, citizenship, expiration date and date of birth. In my 2015 story, I showed how this exact technique permitted access to the same information on Lufthansa customers (this still appears to be the case).

Špaček also reminds readers about the dangers of posting boarding pass barcodes or QR codes online, noting there are several barcode scanning apps and Web sites that can extract text data stored in bar codes and QR codes. Boarding pass bar codes and QR codes usually contain all of the data shown on the front of a boarding pass, and some boarding pass barcodes actually conceal even more personal information than what’s printed on the boarding pass.

As I noted back in 2015, United Airlines treats its customers’ frequent flyer numbers as secret access codes. For example, if you’re looking for your United Mileage Plus number, and you don’t have the original document or member card they mailed to you, good luck finding this information in your email correspondence with the company.

When United does include this code in correspondence, all but the last three characters are replaced with asterisks. The same is true with United’s boarding passes. However, the customer’s full Mileage Plus number is available if you take the time to decode the barcode on any United boarding pass.

Until very recently, if you knew the Mileage Plus number and last name of a United customer, you would have been able to reset their frequent flyer account password simply by guessing the multiple-choice answer to two secret questions about the customer. However, United has since added a third step — requiring the customer to click a link in an email that gets generated when someone successfully guesses the multiple-choice answers to the two secret questions.

It’s crazy how many people post pictures of their boarding pass on various social networking sites, often before and/or during their existing trip. A search on Instagram for the term “boarding pass”, for example, returned more than 91,000 such images. Not all of those images include the full barcode or boarding record locator, but plenty enough do and that’s just one social network.

For anyone interested in how much of today’s airline industry still relies on security by obscurity, check out this excellent talk from last year’s Chaos Communication Congress (CCC) in Berlin by security researchers Karsten Nohl and Nemanja Nikodijevic. Nohl notes that the six digit booking code or PNR is essentially a temporary password issued by airlines that is then summarily printed on all luggage tags and inside all boarding pass barcodes.

“You would imagine that if they treat it as a password equivalent then they would keep it secret like a password,” Nohl said. “Only, they don’t, but rather print it on everything you get from the airline. For instance, on every piece of luggage you have your last name and the six-digit (PNR) code.”

In his talk, Nohl showed how these PNRs are used in code-sharing agreements between and among airlines, meaning that gaining access to someone else’s frequent flyer account may reveal information associated with that customer’s accounts at other airlines.

Nohl and his co-presenter also demonstrated how some third-party travel sites do little to prevent automated programs from rapidly submitting the same last name and changing the PNR, essentially letting an attacker brute-force a targeted customer’s PNR.

My advice: Avoid the temptation to brag online about that upcoming trip or vacation. Thieves looking to rob someone in your area will be delighted to see this kind of information posted online.

Don’t post online pictures of your boarding pass or anything else with a barcode in it (e.g., there are currently 42,000 search results on Instagram for “concert tickets”).

Finally, avoid leaving your boarding pass in the trash at the airport or tucked into that seat-back pocket in front of you before deplaning. Instead, bring it home and shred it. Better still, don’t get a paper boarding pass at all (use a mobile).

I recently heard from a police detective who was seeking help identifying some strange devices found on two Romanian men caught maxing out stolen credit cards at local retailers. Further inspection revealed the devices to be semi-flexible data transfer wands that thieves can use to extract stolen ATM card data from “deep-insert skimmers,” wafer-thin fraud devices made to be hidden inside of the card acceptance slot on a cash machine.

The investigator agreed to share the photos if I kept his identity out of this story. He told KrebsOnSecurity that the two men were thought to be part of a crime gang active in the northeast United States, and that the almost 4-inch orange plastic wands allow thieves to download data from a deep insert skimmer. Depending on how the deep-insert skimmer is built, thieves may be able to use the wands to retrieve card data without having to remove the skimmer from the throat of the ATM.

Deep insert skimmers are different from typical insert skimmers in that they are placed in various positions within the card reader transport, behind the shutter of a motorized card reader and completely hidden from the consumer at the front of the ATM.

Here’s a look at these insert skimmer wands (for want of a better term):

This is what the wand (left) looks like when inserted into a deep-insert skimmer (right):

The following image shows three data transfer wands and three insert skimmers seized from compromised ATMs:

Charlie Harrow, solutions manager for ATM maker NCR Corp., said he has not physically examined the devices pictured above, but that they appear to have a USB interface on one end (the end that plugs into whatever device the crooks use to download stolen card data from the deep-insert skimmer) and a low profile header on the other.

“USB connectors are too big generally to put on a skimmer, especially the newer deep insert skimmers,” Harrow said. “Those devices have very low profile connections such that the overall device thickness is kept to a minimum.”

Once you know about all the ways that skimmer thieves are coming up with to fleece banks and consumers, it’s difficult not to go through life seeing every ATM as potentially compromised. I’m constantly banging and pulling on the poor machines and half expecting half hoping parts to come unglued. I’m always disappointed, but it hasn’t stopped me all the same.

Truthfully, you probably have a better chance of getting physically mugged after withdrawing cash than you do encountering a skimmer in real life. So keep your wits about you when you’re at the ATM, and avoid dodgy-looking and standalone cash machines in low-lit areas, if possible. When possible, stick to ATMs that are physically installed at a bank. And be especially vigilant when withdrawing cash on the weekends; thieves tend to install skimming devices on Saturdays after business hours — when they know the bank won’t be open again for more than 24 hours.

Lastly but most importantly, covering the PIN pad with your hand defeats one key component of most skimmer scams: The spy camera that thieves typically hide somewhere on or near the compromised ATM to capture customers entering their PINs.

Shockingly, few people bother to take this simple, effective step, as detailed in this skimmer tale from 2012, wherein I obtained hours worth of video seized from two ATM skimming operations and saw customer after customer walk up, insert their cards and punch in their digits — all in the clear.

For more on how these insert skimmers work, check out Crooks Go Deep With ‘Deep Insert’ Skimmers. If you’re here because, like me, you find skimmers of all kinds fascinating, please see my series All About Skimmers.