Challenge Simulator · Section 1

IMSI Lookup Simulator

Use sigtran-shell (2G/SS7) or diameter-cli (4G/LTE) to retrieve the IMSI from the simulated HLR/HSS. Watch the protocol stack animate as the request traverses the network.

ℹ Simulated environment. Everything on this page — the sigtran-shell / diameter-cli tools, the HLR/HSS, and the network stack animation — is a self-contained simulation built for the workshop. Nothing here connects to a real network or sends real signaling; the responses are scripted so you can focus on the concepts without needing live SS7/Diameter access.

Challenge MSISDN

+1 (408) 555-3721

2G/3G · HLR Address (GT)

13105550100

4G/LTE · HSS Hostname

hss.workshop.local

Objective

Send the correct command → extract IMSI → submit as flag

sigtran-shell — 2G/SS7 Mode ● CONNECTED

sigtran-shell>

Quick Commands

Protocol Stack · SS7 / MAP (2G)

SIGTRAN transport over IP · MAP over M2PA/SCTP/IP

CLIENT NODE
sigtran-shell client

REMOTE HLR
Home Location Register

SS7 NET
SIGTRAN

Layers:

Application

Protocol

Session/Routing

Transport

Network

Round-trip Timing

Encap: —

Transit: —

Process: —

Return: —

Flag Submission

Submit Your IMSI

Once you've retrieved the IMSI via either the 2G or 4G/LTE command, enter it below. The IMSI is your flag.

Proceed to Section 2 →