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⚠ Don’t rush to buy “bugged” items from marketplaces.

Today, the developers released another “band-aid” fix that apparently didn’t eliminate the dupe but merely slowed it down.
Over the past four days, our bot has caught 4,015 items being transferred for pennies through auto-buy orders on the marketplace.

📊 What the data shows:
• All items had a 7-day trade lock, and for most of them, only 6–14 hours had passed since the lock was set — meaning the items were fresh (recently duped).
• There were also some with a 3–5 day trade lock, which suggests that not all accounts get banned within 24 hours after the dupe.

It seems the developers still don’t understand the dupe mechanics and/or simply can’t fix the problem at this point.

📈 Scale:
If the item dupe has been active for more than a month, then, by the most modest estimates, dupers may possess between 30,000 and 100,000 duped items. What will happen to them next is still unknown.

💰 Interesting notes:
• The Chinese are not only duping items on an industrial scale but also placing fake orders for the gem Trail of Burning Doom, to sell duped items at higher prices on third-party sites.
• In such a short period, the bot recorded:

- one unique Spine Splitter
- Blade of Tears, which was transferred only once (on one of the days)
- items with the gem Trail of Burning Doom - 3,223 pcs
- items with the gem Ionic Vapor - 298 pcs

🤖 What’s next:
The bot continues to monitor the activity of these items on the marketplace.
Posts about new listings are disabled, but if mass transfers start again, I’ll immediately resume autoposting and report it in the group.

The table of all recorded transferred items — [link] (Listing_ID and Asset_ID temporarily removed).
Thanks to everyone following the updates! Monitoring and data collection continue. ❤

10 - Inscribed The Dragon's Soul
10 - Inscribed Enchanted Vision
10 - Inscribed Staff of the Lunar Tree
10 - Inscribed Emissary's Blade
10 - Inscribed Red General's Soul Splitter
10 - Inscribed Catastrophe
10 - Inscribed Icewrack's Fist
10 - Inscribed Bow of the Lone Traveler

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❗️It seems that this ban was an isolated case, while the rest of the accounts with duplicated items remain active to this day and continue to sell their items on Chinese markets such as buff163. Here are just some of them:
[1] • [2] • [3] • [4] • [5]
[6] • [7] • [8] • [9]
[10] • [11] • [12] • [13] • [14]
[15] • [16] • [17] • [18] • [19]
[20] • [21] • [22] • [23] • [24]
[25] • [26] • [27] • [28] • [29]

⚠️ It is worth noting separately the [7] account — a transfer recorded by the bot [view]

📊 On October 18, a transfer of 80 items with an Ethereal Gem was recorded through the Steam Market.
The account(s) had the CNY region, which may indicate that the “market lock” workaround did not fix the duplication exploit, but only slowed it down:
10 - Inscribed The Dragon's Soul
10 - Inscribed Enchanted Vision
10 - Inscribed Staff of the Lunar Tree
10 - Inscribed Emissary's Blade
10 - Inscribed Red General's Soul Splitter
10 - Inscribed Catastrophe
10 - Inscribed Icewrack's Fist
10 - Inscribed Bow of the Lone Traveler

💬 Stasik summed up the results of the Dota 2 exploit investigation:
He stated that he spent $12,000 on the investigation and lost about $650,000 due to the devaluation of his collection.
According to him, the exploit is still not fixed, and Valve has taken no action against the violators.
Stasik announced that he is ending his involvement in the topic and invited everyone to read the full materials on GitHub, Reddit и and Uncle Dan’s Discord.

🔗 Full post on GitHub: [view]

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🆕 Hypothesis on How the Dota 2 Item Dupe Worked

Recently, one of our subscribers sold Catastrophe (Trail of Burning Doom)
on the Steam Market, and a few hours later received a ban with the message: “this account was used for fraud.”
After a short conversation with Steam Support, the ban was lifted, and the transaction was rolled back: the item was returned to the seller, and deleted from the buyer’s inventory.
Interestingly, at the time of inspection, the buyer was not banned — only the seller.

This situation made me review the data we had already collected.

⚙️ How the Dupe Scheme Might Have Worked
Let’s assume the duper used three accounts — [A], [B], and [C]:
1. Items are transferred from [A] → [B] through the Steam Market.
2. Immediately after that, [B] → [C] — the items move further the same way.
3. Then the duper initiates a ban on account [B], after which all its trades are rolled back.

Result: items return to [A] (duplicated), originals remain on [C], and [B] gets banned within 24 hours.

🔍 Why This Seems Plausible
1. After the rollback, Catastrophe returned to the inventory in its original state — without trade or market lock. The same thing was seen in the spreadsheet: for some items, the trade lock timer was not 7 days but 3–4 days.
2. The account received a ban within 24 hours, as Stasik noted in his posts. However, it seems that the ban was initiated by the duper himself.
3. There were often cases where items of the same quality were transferred several times, which could indicate a double transfer [A] → [B] → [C].
4. The duper tried to make items “unique” using Autographed and Corrupted gems, since items of this quality either had no autobuy orders at all, or were priced much lower than regular ones. Example — Golden Wings of the Manticore. Apparently, it was unprofitable to dupe expensive skins, and this could also have been a way to disguise the scheme, making everyone believe the dupe was related to item modifications.

We can conclude that the 7-day market lock partially fixed the dupe.
Our bot recorded two dupe attempts — [1], [2] — but apparently, they were unsuccessful.

💡 A similar dupe already existed in CS2 — after the introduction of the Steam Market “fund hold” mechanic, stickers and skins were being duplicated, as explained by MZKshow in his video.

📣 What’s Happening Now
It seems that after the market-lock fix in Dota 2, dupers switched to TF2.
For a week now, we have been observing how several accounts are transferring cheap skins (example) for amounts up to several thousand dollars per day.
It’s possible that a variation of the same scheme is being used — but this time not to dupe items, but balance: one of the accounts gets banned, initiating a rollback of transactions, and the funds return to the first account and remain with the third.

Monitoring of suspicious activities on the Steam Market continues, and all new cases will be covered on the channel. You can also track activity manually (link) — in the main group, hourly statistics are pinned. Additionally, there are separate groups for Dota 2, TF2, and CS2 — these are temporary tools that will be improved over time and may later move into our main [Chat].

🤖 Unfortunately, the new bot is currently working in slow mode and captures about 1/10 of all sales, but even based on this data, it can be assumed that GabeN earns around $3 million per day just from Steam Market commissions. ↗

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When the phrase “from trash to knife” took on a new meaning 🔫 → 🔫

In the previous post, we discussed the duplication of runes/gems — a situation where the same rune could be inserted into multiple slots of one item, creating duplicates.
In short, the server check only verified that the asset_id (the item itself) existed in the inventory, not that it was unique. Because of that, when sending the request k_EMsgGCAddItemToSocket (1088), the server accepted repeated gem_item_id values as valid, allowing one rune to generate multiple copies.

There’s an important detail that no one mentioned: duplication of asset_id affected not only runes but also any items involved in crafting and item combination. This exploit was fixed today.

🔵📚 Crownfall treasures dupe:
It was possible to get nine by using the bundle packaging request. The server accepted repeated asset_id values as different items, so the same treasure turned into a full bundle of nine.
Crownfall treasures contained valuable sets, including the Arcana set for Crystal Maiden and the Servant of Scree’Auk Baby Roshan.

🔫 What else could be duped:
It seems the same principle applied to Frostivus / Diretide crafting — the server could accept repeated asset_id values as different items, so top-tier sets were effectively crafted from a single first-tier set.

If this worked in Dota 2, it’s possible that similar vulnerabilities existed in CS2, for example, in trade-up contracts.

🛡 Internal dupe protection:
Interestingly, when skins are duped, Valve’s internal protection apparently triggers — during such operations, the Game Coordinator (GC) crashes for all players. A similar situation was described by voidsploit in his post.
The more items are duplicated, the longer the GC stays down, which could be indirect evidence that the original dupe — the one our group started tracking — worked through the Steam Market, since Valve would have quickly detected and fixed a large-scale dupe happening inside the GC itself.

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It’s been a while since the last news ☕️

👁 Recently, small activity was recorded several times involving item “transfers” through the Community Market. In all cases, accounts with CNY and HKD regions were involved:
[ 1 ] 2025-12-31
[ 2 ] 2026-01-09 *the bot broke and didn’t post
[ 3 ] 2026-01-11
In total, ~80 items were transferred, which is significantly less than previous volumes. This may indicate that dupers are looking for a new way to transfer items through the Community Market or are trying to adapt the existing one to current restrictions.

😲 Also, if previously it was only possible to identify duped items by indirect signs and guesses, now it can be done directly via the Steam API, without any guessing.

In short: every item has a current ID that changes after any actions with it (for example, a trade or a Community Market sale), and an original ID that is static and never changes. This is what lets you determine whether an item was duped ❗️

More details on the method and the full list of items with original IDs are collected in a separate Steam guide: [view guide] *the guide is still being updated

By the way, not only duped bugged items were found, but also high-tier items such as Platinum Baby Roshan and legacy couriers. Their full list will be published later.

Join our chat to stay up to date with the latest updates @DupeBustersChat ☕️ [ Reddit ] • [ GitHub ]