Venmo. The App for Virtual Ballers.

I recently went on a trip which required hanging out in a couple of airport terminals. While waiting on my flights I saw the usual scene: a sea of people staring down at their phones. I am not going to delve into the obvious security concerns (whole different topic), but I was able to see many home screens from my vantage point, and I noticed a few consistent apps. One was a blue square/circle with a white ‘V’ in it: Venmo, the social media payment app.

Full disclosure: I am not a Venmo person. I live in Apple’s walled garden and like to use Apple Pay whenever I can. I am reluctant to provide any merchant or service any financial information as I have been caught up in a couple of data breaches, specifically, Target and Home Depot. While those two incidents involved POS weaknesses, the pain they caused made me extremely paranoid when it comes to my financial information.

Not everyone has that attitude, however. While conducting testing for this post I was amazed at how many people in my contact list use Venmo. My spouse even uses it (she had to show me the ropes when I first fired up the app). As of April of 2019, Venmo reported 40 million active users with payment volume around $21 million; it is expected that payment volume will hit $100 million for the entirety of 2019. Comparatively, it sits behind its parent company, PayPal, and Amazon Pay. Third isn’t too shabby in the mobile payment space.

Because Venmo is owned by PayPal, users can, at many merchants, use Venmo where PayPal is accepted, but using it at merchants isn’t Venmo’s main draw. It is being able to pay people for whatever reason without having to use cash…especially since most people don’t accept cards and a majority of people, I would argue, don’t carry cash around. Venmo is also a social media app. It has a feed, similar to other social media feeds, that shows you what your “friends” are buying and selling. For example, in my Venmo social feed I saw payments for “schnacks,” daycare, date nights, booze, haircuts, groceries, picking up prescription medications, pizza, and a corn hole tournament. These were person-to-person transactions, not person-to-merchant. Paying people for whatever just by clicking a few buttons can be a lot easier than paying with cash (again, who does that nowadays???) or trying to figure out who accepts cards and who doesn’t. For some small merchants, it may be cheaper to use Venmo versus accepting cards and having to pay bank/card transaction fees.

There is also a public feed that shows what people (who you are not friends with) are buying and selling. This is notable as the default setting for transactions is “public” (more on that later).

This idea of a social feed is important. File it away for now because I will bring it up later when discussing iOS.

Like everything else, people have found a way to use Venmo for questionable activities. I found a site, Vicemo, that uses Venmo’s public API to track what it thinks are payments for booze, strippers, and narcotics. In 2017 there was a study that found a third of Venmo users have paid for weed, cocaine, and Adderall with Venmo, and that 21 percent of Venmo users have used it to make bets on sporting events.

Is This Useful?

Generally speaking, having access to this data can be beneficial as it can be considered pattern-of-life (POL) data. A lot can be gleaned from knowing what a person purchases or sells, and from/to whom they are purchasing or selling. Just think about the entry in my social feed regarding the prescription medication. Based on that entry, I may be able to deduce that person has a particular medical condition if the payment note has enough information in it. I could also look in my public feed and find similar bits of information.

This data can be a gold mine for investigators, and I would argue an investigator’s imagination is the limit for its application. For example, think of the drug dealer who is using Venmo for payments. Want to know who the buyers are or who the source is? Just pull the Venmo data, do some analysis, and start slinging subpoenas/court orders/search warrants for Venmo account information. What about the local fence who operates in your jurisdiction? Want to know who the fence sold some stolen property to? Same scenario.

My point is people do not randomly give money away. They are paying for things they need, want, or are significant to them in some fashion. Understanding this allows an investigator to draw conclusions by taking this data and applying some deductive reasoning.

POL data is extremely useful. There has been a lot of research during the past couple of years that has shown just how much data about our lives is collected by our mobile devices. This data, when interpreted correctly, can be powerful.

The Setup

As usual, just a few notes on the hardware/software used.

Pixel 3:   Android 10 (patch level 9/5/19), rooted, Venmo version 7.40.0 (1539)

iPhone SE:  iOS 13.2, non-jailbroken, Venmo version 7.40.1 (1)

For testing I used a couple of pre-paid cards that I picked up at a Wal-Mart. I had to register the cards first with their respective “banks”, and then load them into Venmo; if you were to use a card issued to you the registration part would not be necessary. Also, you have the option to link an actual bank account to your Venmo account, which is something I did NOT do.

I will add that during my analysis, I did not find where either OS stored the actual card information, even though I could see it within the UI. It may be there, encoded somehow, but I didn’t see it.

Android

Before we go down the forensic road, I want to show what a transaction screen looks like in the Android UI. It will help make things clearer.

Figure 1 shows the payment screen. In the red box is the transaction recipient. While I didn’t do it during testing, and you can add more than one recipient here. The green box is obvious…the amount of money I am sending. The blue box shows the note that is attached to the payment. Venmo requires that there be something in this field, even if it is an emoji. The orange box is the share-level of the transaction. It can be set to Public (everyone on Venmo sees it), Friends Only, or Private (just you and the recipient see the transaction). The default is Public, but you can change the default setting from the Settings menu.

Figure 1.png
Figure 1.  Android payment UI.

The purple box dictates what happens to this transaction. If you hit “Pay” the money is sent. If you hit “Request” a request goes to the transaction recipient who can either pay or decline to pay the requested amount. More on those in a bit.

There is one other way to send someone money. An intended transaction recipient can display a QR code on their device, which the sender can scan, fill out the note and amount fields, and then hit “Pay” or “Request.”

Venmo data in Android resides in /data/data/com.venmo. Because of new technical hurdles with Android 10 on the Pixel 3, I had to copy the folder over to the /sdcard/Download folder via shell and then run an ADB pull from there.

Unlike my previous post about Wickr, Venmo databases are pretty straight forward. There are three files of interest, with the biggie being venmo.sqlite. The database can be found in ./databases folder. See Figure 2.

Figure 2.png
Figure 2.  Available databases in Android.

There is an additional database of interest here, too, named mparticle.db, which I will discuss shortly.

This database contains all of the transaction information along with any comments about transactions and any responses to the transactions. Take a look at the screen shot in Figure 3, which shows a completed transaction. The iOS device paid the Android device $5.00 on 10/31/2019 at 9:56 PM (EDT). The note sent with the payment was “For the testing stuff. My first payment.” The Android device responded to the comment (no time stamp is seen).

 

Figure 3.png
Figure 3. Android screenshot of a completed payment.

Figure 4 shows the table marvin_stories. You will notice transactions are called stories, and that timestamps are stored in Zulu time in human-readable format.

Figure 4.png
Figure 4.  The marvin_stories table.

The columns of interest here are story_data_created, story_note, and story_audience. However, if you want to get all of that information and more in one place, you need to look at the contents of the last column, story_blob. See Figure 5.

Figure 5
Figure 5.  Transaction information from the story_blob column.

The contents of these cells are broken up in to three parts. Actor (transaction sender), transaction information, target (transaction recipient). If you recall from Figure 2, the iOS device sent the Android device $5.00. So, the actor, the iOS device, is seen in the green box. There you can see the action (“pay” the Android device), the display name, friend status, the user ID for that account, last name, how many mutual friends we may have, and the actual user name (Josh-Hickman-19).

In the purple box you find the transaction information: the amount of money (5.0 – Venmo drops tailing zeros occasionally), the date the transaction was created and completed, the transaction ID (more on that in a moment), the note that came with the payment, and the fact that it was “settled.” The status of “settled” is the only status I have seen and I have not been able to change the value in this field.

The orange box has the transaction recipient, or the target, which is the Android device (ThisIs-DFIR). It has the same information as the green box.

When a transaction is completed in Venmo, both parties get an email notification. The transaction ID seen in the purple box in Figure 5, also appears in the email (Figure 6, red box).

Figure 6
Figure 6.  Email with transaction ID.

The column story_likes_blob is simple, and is seen in the red box in Figure 7. If there is a value present in this cell it means someone “liked” the transaction. An example of how that appears in the UI is seen in Figure 8.

Figure 7.png
Figure 7.  story_likes_blob column.

 

Figure 8.png
Figure 8.  A “liked” transaction.

Values in the column are also stored in JSON. The “like” for the transaction in Figure 8 is displayed in Figure 9. As you can see, much of the information in the transaction JSON data is also present here.

Figure 9.png
Figure 9.  A “like” in the database.

A note about the privacy level of transactions. After a transaction is completed, it goes into a social feed. The feed it goes into is dependent upon what privacy level setting was chosen at the time the transaction was sent; however, the transaction privacy level can be changed by any party that was part of the transaction at any time. If the privacy level is changed, the transaction is removed from the original feed and placed in the new feed.

The reason privacy level is important is that people not part of the transaction may be able comment on it (because they can see it). Their ability to do so is dependent upon the privacy level. For example, if I set the privacy level of a transaction as “Private,” only the other person (or persons if there is more than one party) can comment on the transaction. If I set the privacy level to “Friends Only,” then my “friends” in Venmo can comment on the transaction along with the parties involved. If I set the privacy level to “Public” anyone on Venmo can comment on the transaction.

Figure 10 shows a transaction that has a comment. As you can see in the blue box, I set the privacy level of this particular transaction to “Friends Only,” which means any of my Venmo “friends” could add a comment to this transaction if they chose to do so.

Figure 10.png
Figure 10.  A transaction with a comment.

Getting back to the database, the table comments contains information about comments made on transactions. See Figure 11.

Figure 11
Figure 11.  The comments table.

Four columns are important here. The first is obvious: the comment_message column (orange box). This contains all of the comments made. The column next to it, created_time is the time the comment was left (blue box). The column in the red box, comment_story_owner, is important as it links the comment back to the transaction. The values in this column correspond to the values the story_id column in the marvin_stories table. Note that some transactions may not have entries in the table if no one comments on them.

The column seen the green box, comment_user_blob contains JSON data, and contains much of the same JSON data seen in previous figures. This documents who made the comment. If you are in a hurry and don’t want to look at the JSON data, you can clearly see them username value of the user who made the comment in the cell. 🙂

The last table in this database is table_person, and contains data about anyone with whom you have conducted a transaction. The data is simple. See Figure 12.

Figure 12
Figure 12.  table_person.

The next file of interest is also a database: mparticle.db. It resides in the same location as venmo.sqlite. The only data I was able to generate in this database appears in the attributes table. See Figure 13.

Figure 13
Figure 13.  Attributes from the mparticle.db.

The columns attribute_key, attribute_value, and created_time (stored in Unix Epoch) are straight forward. One note about the time, though. Users are able to change their display names and phone numbers, and if they do, the created_time values will also change. I changed my first and last name, but left the phone number. The created_time for the phone number in Figure 13 corresponds to when I created the account, but the other values correspond to the time I last made changes to my first and last name.

The last file is venmo.xml, and it resides in ./shared_prefs folder. This file contains some basic information along with an additional nugget or two. Figure 14 shows the first part of the file.

Figure 14.png
Figure 14  vemo.xml, Part 1.

In the green box is the userID for my “top friend.” Seeing how I had only one friend for this particular account, the value relates back to the account on the iOS device. The blue box has the timestamp for the last time time I sync’d my contacts, the yellow box has the email account associated with the Android account, and the red box contains the userID and last last name associated with the Android account.

Figure 15 has three items, the full name (display name) and phone number associated with the account (red box), and the display first name (blue box). The names seen here correspond to the values seen in the attributes table in the mparticle.db.

Figure 15.png
Figure 15.  venmo.xml, Part 2.

Figure 16 has two items. The first is seen in the green box, and is the user name on the Android account. The other, the user_balance_string value, corresponds to the amount of money this account has in Venmo, which can be seen in the blue box in Figure 17.

Figure 16.png
Figure 16.  venmo.xml, Part 3.
Figure 17.png
Figure 17.  Venmo balance.

When a transaction is completed in Venmo, the money goes into what I like to think of as a staging area. This staging area holds the funds, and you can either use them in other transactions, or transfer them to a bank account if you have one linked. You can also have the balance sent to a credit card, but the credit card has to be a certain type, and my pre-paid card didn’t meet the criteria.

Paying someone via “Pay” or scanning a QR code is not the only way a user can get paid. A user can request payment. Remember the “Request” button in Figure 1? Well, there is a way to tell if that was the method by which funds were transferred. See Figure 18.

Figure 18.png
Figure 18.  The “charge” action.

Figure 18 has the same data in the same green, purple, and orange boxes as seen in Figure 5. The only difference here is the “action” field at the top of the green box has changed from “pay” to “charge” (red arrow). This indicates the transaction occurred because the Actor (the transaction sender in the green box) box requested payment, and the Target (the transaction recipient in the orange box) granted the request. As a side note, you can see that there are more digits in the “amount” field this time (purple box).

I tried requesting payment and declining the request three times to see what was left behind. Interestingly enough, there is no record of those three requests anywhere. Venmo may keep this data server side, but you will not get it from the device.

That’s it for Android. I had to triple check everything because I thought I was missing something, again, because of the amount of work involved in the Wickr post. That being said, there are other capabilities of Venmo I did not test, such as Facebook, Snapchat, and Twitter integration, along with linking my bank account. As I previously mentioned, I was surprised I did not find any references to the bank card used for transactions; it may be there, but I did not find it.

iOS

Good news: Venmo data is available in an encrypted iOS backup in iOS 13.2, so I assume that is the same for previous iOS versions. This is great because that means all an examiner needs to do is create a backup, or use their preferred forensic extraction tool to get this data. Nothing else was necessary.

iOS contains the same data as the Android version, just in a different format. There was also a few additional bits of data I found that could be useful in certain situations, and I will review that as well.

Transaction information is stored in the net.kortina.labs.Venmo/Documents folder. Remember when I mentioned the idea of a social feed being important? Well, iOS is why. Unlike Android, iOS stores Venmo transactions in three different files. Which file it stores a transaction in depends on the privacy level set at the time of the transaction. See Figure 19.

Figure 19.png
Figure 19.  Contents of the net.kortina.labs.Venmo/Documents folder.

The files FriendsFeed, PrivateFeed, and PublicFeed“should look familiar. These are the three privacy level settings for Venmo transactions. These three files are binary plist files. Figure 20 shows the same transaction as seen in Figure 5, and comes from the PrivateFeed file.

Figure 20.png
Figure 20.  Same transaction as Figure 5.

Reading this is a little tricky as the data is not as neatly grouped as that in the Android database. First, the file stores data from the bottom up, chronologically speaking. Second, this transaction was found in the PrivacyFeed file (remember the privacy level setting seen in the orange box in Figure 1). To help see the comparison to Android, I grouped the actor, transaction information, and target data using the same green, purple, and orange boxes. In the red box is the comment the Android account left for this transaction, complete with the timestamp; see Figure 21 for how this looks in the iOS UI.

Figure 21.PNG
Figure 21.  Comment from Figure 20.

One thing you will notice is that the “action” and status fields are missing. I looked in this file and the only time these fields showed was the most recent transaction that occurred with the privacy level set to Private (at the top of the PrivacyFeed file). The rest of the transactions in this feed did not have an action or status associated with them. I may not necessarily be reading this bplist file correctly, so if someone else knows, please let me know so I can update this post.

Figure 22 was the most recent “Private” transaction on the iOS account. Figure 23 shows the data in the bplist file with the usual groupings (green box = actor, purple box = transaction information, orange box = target), and Figure 24 shows that same transaction in the venmo.sqlite database from the Android device. Notice the “action” and “status” fields are present in Figure 23.

Figure 22.png
Figure 22.  Last “private” transaction on the iOS account.
Figure 23.png
Figure 23.  bplist entry for the transaction in Figure 22.
Figure 24.png
Figure 24.  Android entry for the comparison.

Figure 25 shows the “Request” transaction from Figure 18. Again, I used the same colored boxes to the group the data. Note the red box at the bottom; it contains the privacy level setting for the transaction.

Figure 25.png
Figure 25.  The “request” transaction from the iOS point of view.

Since we are on transactions I will head over to the “FriendsFeed” for just a moment. This is an additional bit of information that I saw in iOS that was not present in Android. This feed contains a lot of information about your Venmo friends’ transactions. The data is not as verbose as the data about my transactions, but you can see when transactions occur, the transaction information (time, note, and transaction ID – purple box), the actor (green box) and target (orange box). Notice the action and status fields are missing. Because the target and actor are not aware of this blog post, I have redacted pertinent information. See Figure 26.

Figure 26
Figure 26.  A transaction by one of my Venmo friends.

If you recall from Figure 19, there is a database present named Model.sqlite. This database contains information about a user’s Venmo friends. The table ZMANAGEDUSER contains friend information. See Figure 27.

Figure 27.png
Figure 27.  Venmo friends.

These columns are fairly self-explanatory. ZCREATEDAT is the time the user account was created. ZDISPLAYNAME is the display name for the account. ZFAMILYNAME is the user’s last name. ZGIVENNAME is the user’s first name. ZIDENTIFER is the user’s userID, and ZUSERNAME is the user’s user name.

The PublicFeed file contains the same data as the Private and Friends versions, but includes data about people with whom the user is not friends with.

The next interesting file is net.kortina.labs.Venmo.plist which is found in the ./Library/Preferences folder. The top part of the file is seen in Figure 28.

Figure 28.png
Figure 28.  net.kortina.labs.Venmo.plist, Part 1.

The data in the red square is the iOS equivalent to the Android data seen in Figure 13. The blue square references Venmo friends. I expanded it in Figure 29.

Figure 29.png
Figure 29. plist friends from net.kortina.labs.Venmo.plist.

The data in Figure 29 comes from the user’s contact list on device.

Figure 30 is the rest of the net.kortina.labs.Venmo.plist. The data in the red squares are the display name, the email address associated with the account, and the phone number associated with the account. You can see, based on the data in the blue square, that I changed my default privacy level to “Friends.”

Figure 30.png
Figure 30. net.kortina.labs.Venmo.plist, Part 2.

Figure 31 shows the file com.google.gmp.measurement.plist found in the same directory as the previous file. The app version and the first time the app was opened can be found in the red and blue squares, respectively.

Figure 31.png
Figure 31. com.google.gmp.measurement.plist.

That’s it for iOS. The data is readily available, and includes data that is not necessarily present in Android. As with Android, I did not find any information on the card attached to the account, and I did not test any of the linking or integration abilities.

Conclusion

Virtual payments are a thing, no doubt about it. Amazon Pay, PayPal, Venmo, Zelle and many others along with the platform-specific pay services like Apple Pay and Google Pay are all trying to help people pay for things. Venmo is ranked 3rd in that group, and stands out from the crowd by mixing payment services with social media capabilities.

Venmo contains POL data, which can be valuable, and the data is versatile. It can be used to extrapolate information about the user which can be useful for investigators.

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