A Concert Seat from a LinkedIn Lead

Privacy note: the target’s name, LinkedIn URL, and every social-media handle, profile ID, and search URL that could identify them have been removed from this writeup. No account is named or linked. No person or organisation was contacted. Only publicly accessible information was used, and only the detail needed to explain the method is reproduced here.

The task

One LinkedIn profile as an identity anchor, four things to find:

1. the place the person visited on 17 September 2023,
2. the seat they were assigned there,
3. the venue name in the local language,
4. a normalised seat string with its components joined by hyphens.

LinkedIn itself carried no convenient “I was here on 17 Sept 2023” post. So the decisive move was never find the LinkedIn post — it was a cross-platform pivot to publicly linked accounts holding older travel content.

The answer

Diver26{고척스카이돔_2-T12-E-18}

Step 1 — Use LinkedIn only as an identity anchor

From the supplied profile I took exactly four things: the profile photo, the name variants, one education/career detail, and the style of handle the person tended to reuse. Name and URL stay out of this writeup.

The goal wasn’t to extract anything private. It was to find a publicly provable link from the anchor to older travel content on the platform where that content actually lives.

Step 2 — Confirm the pivot on a second platform

The chain from LinkedIn to the person’s main image-sharing account is the part I’m deliberately keeping vague — spelled out with handles, it’s a deanonymisation recipe. The shape, in method terms: a publicly reachable profile on one platform carried, in its bio, a handle matching an account on another. That reciprocal reference — account A naming account B, and B’s content fitting the LinkedIn anchor — is what turns a guess into a confirmed pivot.

Keep the shape, not the accounts: one platform’s bio field naming another platform’s handle is the single most common way a cross-platform identity link becomes provable. People maintain that link themselves, for their own convenience, and it outlives the post you originally wanted.

Some linked profiles only showed older content behind a partial login wall. Fine — those served as continuity and alias corroboration. The proof of seat and venue came from the vlog frame.

Step 3 — Find the Korea content

The pivot led to a travel vlog whose Chinese title translates to roughly:

Korea vlog: eating and drinking my way through a weekend, and catching a BLACKPINK concert while I’m at it.

One title, three previously unconnected elements fused: a trip to South Korea, a BLACKPINK concert, a weekend stay in the right window.

The platform’s own search sat partly behind a login wall. The clip didn’t — recoverable through the public profile, then examined frame by frame.

Step 4 — Verify the event by date

BLACKPINK’s BORN PINK world-tour finale in Seoul ran two nights — 16 and 17 September 2023, both at the Gocheok Sky Dome. The concert in the vlog matched the challenge’s date exactly.

Sources:

• YG Life — finale on 16–17 September at Gocheok Sky Dome
• Yonhap News Agency — event announcement
• YG Entertainment — official on-site notice for 17 September

Step 5 — The ticket as primary evidence

A physical ticket is clearly visible in the vlog. Only the fields the challenge needs matter; the reservation numbers and booking timestamps are blurred below — personal to the purchase, irrelevant to the solve.

The full seat string in clear type: 2층 T12구역 E열 18번 — the only contested character on the ticket is the T.

The readable fields:

2023년 09월17일(일) 오후 6시00분
장소: 고척스카이돔
2층 T12구역 E열 18번

Translating the ticket fields

A second ticket for the adjacent seat (19번) peeks out underneath. The one held in the foreground reads 18번. That’s the answer.

Step 6 — Why the section is T12, not 112

The hardest detail in the whole solve was one character:

T12구역

At small size and an angle, a capital T reads as a 1. I read 112구역 first, and it produced a wrong flag. Three details settle it as T12:

1. In the enlarged frame the horizontal crossbar of the T is visible.
2. The second ticket underneath shows the same section.
3. The venue’s official seat map defines sections T11–T17 — so T12 is a valid section, and the numeric blocks don’t run that high in that stand.

Source: Official Gocheok Sky Dome seat map

The seat map lists, alongside the numeric blocks:

T01–T07
T11–T17
S01–S16

The map alone can’t prove which character is printed on the ticket. What it can do is make one reading structurally valid and the other implausible — and combined with the crossbar and the second ticket, that’s enough.

Step 7 — The venue name in the local language

The challenge wants the venue in the local language, and the Seoul Facilities Corporation’s own site settles the spelling:

고척스카이돔

Not the English “Gocheok Sky Dome”. That exact string goes in the flag.

Sources:

• Official Gocheok Sky Dome site
• Official facility description

Step 8 — Normalise the seat into the flag format

The full Korean seat string:

2층 T12구역 E열 18번

Strip the descriptive suffixes:

Join with hyphens, prepend the local venue name:

Diver26{고척스카이돔_2-T12-E-18}

Takeaways

A self-maintained bio link is the strongest cross-platform pivot you’ll get. The whole solve turned on one bio field naming another account. People keep that link current themselves; it long outlives the post you first wanted.

Separate the publication date from the visit date. A visit on 17 September doesn’t have to appear in a post published on 17 September. Travel vlogs go up days or weeks later — filter by upload date and you hide the evidence from yourself.

Check every character against a second source. T12 vs 112 is the whole difference between a right and a wrong flag. The adjacent ticket, the enlargement, and the seat map’s valid T-sections all had to agree before the reading was safe.

Don’t assume a “seat” means a flight. The lead was a travel vlog, so a flight seat looked plausible at first. But the challenge’s own template — level, section, row, seat — describes a venue, not an aircraft. Read the flag format as evidence.

Document only what you need. The frame contained extra reservation data; only the crop required for the solve was used, and no identifying account is named here.

Sources

Only non-personal, institutional sources are listed. The individual’s social accounts used for the pivot are deliberately omitted.

1. YG Life — BLACKPINK finale, 16–17 September 2023
2. Yonhap News Agency — venue and dates
3. YG Entertainment — official event notice
4. Official Gocheok Sky Dome site
5. Official seat map
6. Official facility description

Challenge from Diver26 CTF. Public sources only.