T3 fonts being used for no reason?

Question

When I use pdflatex test.tex to compile the simple file:

\documentclass{article}
\begin{document}
Hello \S world! 
\end{document}

the symbol \S is rendered using the (rasterized) T3 font:
<C:\Users\laure\AppData\Local\MiKTeX\fonts/pk/ljfour/jknappen/ec/dpi600\tcrm100 0.pk>

whereas the rest of the text is rendered using the standard LaTeX font
<C:/Program Files/MiKTeX/fonts/type1/public/amsfonts/cm/cmr10.pfb>

What is the reason for this? There seems to be no problem when I use e.g. Overleaf to compile this file. Here is test.log:

This is pdfTeX, Version 3.14159265-2.6-1.40.21 (MiKTeX 20.7) (preloaded format=pdflatex 2020.9.2)  3 SEP 2020 18:24
entering extended mode
**./test.tex
(test.tex
LaTeX2e  patch level 5
L3 programming layer 
("C:\Program Files\MiKTeX\tex/latex/base\article.cls"
Document Class: article 2019/12/20 v1.4l Standard LaTeX document class
("C:\Program Files\MiKTeX\tex/latex/base\size10.clo"
File: size10.clo 2019/12/20 v1.4l Standard LaTeX file (size option)
)
\c@part=\count168
\c@section=\count169
\c@subsection=\count170
\c@subsubsection=\count171
\c@paragraph=\count172
\c@subparagraph=\count173
\c@figure=\count174
\c@table=\count175
\abovecaptionskip=\skip47
\belowcaptionskip=\skip48
\bibindent=\dimen134
)
("C:\Program Files\MiKTeX\tex/latex/l3backend\l3backend-pdfmode.def"
File: l3backend-pdfmode.def 2020-08-07 L3 backend support: PDF mode
\l__kernel_color_stack_int=\count176
\l__pdf_internal_box=\box45
)
No file test.aux.
\openout1 = `test.aux'.

LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 2.
LaTeX Font Info:    ... okay on input line 2.
LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 2.
LaTeX Font Info:    ... okay on input line 2.
LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 2.
LaTeX Font Info:    ... okay on input line 2.
LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 2.
LaTeX Font Info:    ... okay on input line 2.
LaTeX Font Info:    Checking defaults for TS1/cmr/m/n on input line 2.
LaTeX Font Info:    ... okay on input line 2.
LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 2.
LaTeX Font Info:    ... okay on input line 2.
LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 2.
LaTeX Font Info:    ... okay on input line 2.
[1

{C:/Users/laure/AppData/Local/MiKTeX/pdftex/config/pdftex.map}] (test.aux) ) 
Here is how much of TeX's memory you used:
 362 strings out of 481212
 6153 string characters out of 2915728
 241955 words of memory out of 3000000
 16035 multiletter control sequences out of 15000+200000
 535423 words of font info for 30 fonts, out of 3000000 for 9000
 1141 hyphenation exceptions out of 8191
 25i,4n,25p,141b,97s stack positions out of 5000i,500n,10000p,200000b,50000s
 
Output written on test.pdf (1 page, 13285 bytes).
PDF statistics:
 15 PDF objects out of 1000 (max. 8388607)
 0 named destinations out of 1000 (max. 500000)
 1 words of extra memory for PDF output out of 10000 (max. 10000000)

Answer 1

Thanks to everybody for the quick responses! The problem is resolved now. There were two causes.

• I had installed MiKTeX using the "Install MiKTeX for anyone who uses this computer (all users)". The install guide recommends against this because it can be "complicated and error prone". They were right! This maintains two profiles and sets of packages that need to be kept in sync. I didn't realize that.
• I had to install the cm-super package, which is not one of the standard packages that comes with a fresh MiKTeX installation. It really should be though...

After reinstalling MiKTeX using the "only for me" option and installing cm-super through the package manager, the same code I posted before compiled properly.