Sirios Discovers High-Potential Gold Halo in Western Sector of Aquilon Project in Eeyou Istchee James Bay, Quebec

Montreal, December 4, 2025 - Sirios Resources Inc. (TSXV: SOI) is pleased to report assay results from the 2025 summer diamond drilling campaign on its Aquilon gold project, located in Eeyou Istchee James Bay, Quebec.​

Thirteen drill holes totaling 5,420 metres were completed in the summer of 2025. Targets were grouped in a previously underexplored area located west of the historical gold showings.​

Highlights

Discovery of a strongly anomalous gold halo hosted in felsic volcanic rocks
The anomalous zone extends over more than one kilometre in length and several hundred metres in width and remains open in all directions, indicating significant potential for expansion.

The halo is defined by 538 core samples from six drill holes, totaling 601 metres of discontinuous intervals.

Gold grades are locally up to 10.3 g/t Au, with a weighted average grade of 0.26 g/t Au across the halo.

The gold-mineralized halo forms a north-south-trending corridor dipping eastward, consistent with the geological and structural interpretation for this sector of the Aquilon project.​

Key drill intervals
Hole AQ25-119:

• 2.55 g/t Au over 4.8 m, including 10.3 g/t Au over 1.0 m
• 5.51 g/t Au over 1.0 m
• 2.34 g/t Au over 1.1 m
• 0.95 g/t Au over 3.7 m, including 2.32 g/t Au over 0.9 m

Hole AQ25-118:

• 1.12 g/t Au over 4.0 m, including 3.01 g/t Au over 1.0 m
• 2.85 g/t Au over 1.2 m
• 0.92 g/t Au over 5.1 m, including 2.31 g/t Au over 1.1 m
• 1.08 g/t Au over 4.0 m, including 2.81 g/t Au over 1.0 m

Hole AQ25-113: 2.78 g/t Au over 1.2 m

Hole AQ25-123: 2.09 g/t Au over 1.0 m

Location of the 2025 drilling program

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2025 Exploration Drilling Program - Results

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Metallogenic review and additional sampling
The 2025 drilling results outline a new mineralization context on the Aquilon project, characterized by a few high-grade gold intervals surrounded by a lower-grade but broadly distributed halo within a large rock volume. Sirios has initiated a review of lithogeochemical data and metallogenic models applicable to Aquilon.​

Following the drilling results, an additional core sampling program totaling 1,496 metres was completed last week to infill unsampled intervals within the gold corridor. These forthcoming assay results will help refine the corridor's geometry and average grades.​

The western sector of Aquilon had already emerged as a priority area following the delineation of gold-in-soil anomalies during 2023 and 2024 sampling campaigns. The integration of these soil surveys with detailed geological interpretation and a high-resolution drone magnetic survey completed in 2025 led to the definition of the targets tested in the current drilling program.

The drilling program is funded by Sumitomo Metal Mining Canada (Sumitomo), with Sirios as operator. By completing this program, Sumitomo is entitled to gain a 51% interest in the Aquilon project as its commitment in Aquilon then exceeding $4.8 million (see press release dated 12/19/2022).

About the Aquilon Project
The Aquilon gold project consists of 140 mineral claims covering an area of 68 km². It is located in Eeyou Istchee James Bay, Quebec, 10 km south of the Laforge-1 hydroelectric power station and is easily accessible by all-season roads. To date, 32 gold showings have been discovered on the project. Some drill intercepts from the Aquilon project are among the highest grades obtained in Quebec, including 12,906.5 g/t Au over 0.2 m (Lingo showing), 3,527.4 g/t Au over 0.4 m (Moman showing), and 133.67 g/t Au over 0.8 m (Fleur-de-Lys showing) (ref. press releases of 26/06/2008 and 19/01/2011). Additional information is available on the recently updated Aquilon webpage at sirios.com/en/aquilon.

Analytical quality control
All NQ caliber drill cores from the Aquilon project were logged and sampled by Sirios personnel. The cores were split in half, with one half sent to a certified commercial laboratory for analysis and the other half retained for future reference. A strict QA/QC program was implemented, incorporating blanks and certified reference standards into the sample sequence. Gold assays were performed by ALS Global using fire assay with an atomic absorption finish on a 50 g subsample. Samples returning greater than 1 g/t Au, as well as those containing visible gold, were re-assayed by fire assay with metallic screening on a 1 kg sample.

Dominique Doucet, P.Eng. and Roger Moar, P.Geo. qualified persons under National Instrument 43-101, have reviewed and approved the scientific and technical information in this press release.

About Sirios Resources
Sirios Resources is a mining exploration company based in Quebec, focused on developing its portfolio of high-potential gold projects in the Eeyou Istchee James Bay, Canada.

Cautionary Note Regarding Forward-Looking Statements
This press release contains "forward-looking statements" within the meaning of applicable Canadian securities laws based on expectations, estimates and projections as of the date of this press release. Forward-looking statements involve risks, uncertainties and other factors that could cause actual events, results, performance, expectations and opportunities to differ materially from those expressed or implied by such forward-looking statements. Factors that could cause actual results to differ materially from those indicated in such forward-looking statements include, but are not limited to: capital and operating costs that differ materially from estimates; the tentative nature of metallurgical test results; delays or failures in obtaining required governmental, environmental or other approvals; uncertainties related to the availability and cost of necessary financing in the future changes in financial markets; inflation; fluctuations in metal prices; delays in project development; other risks relating to the mineral exploration and development industry; and risks disclosed in public filings of the Company on SEDAR at www. sedar.com. Although the Company believes that the assumptions and factors used in preparing the forward-looking statements contained in this news release are reasonable, readers should not place undue reliance on this information, which speaks only as of the date of this news release, and there can be no assurance that such events will occur or occur within the time periods presented. The Company disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by applicable law.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

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