Malicious PDF — malware analysis report

Static analysis result for SHA-256 40291497bb9c88a6…

MALICIOUS

PDF

97.5 KB Created: 2021-06-27 12:09:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: af111536c08eaf1f988d170b561068b3 SHA-1: 7b1de6262ee93201c2720c26bf28bad6a11da5fb SHA-256: 40291497bb9c88a6b71351b0a957a1d118c2bd4b00c24e3531859e4507edde98
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress upload directories. The ML classifier strongly indicated maliciousness, and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests this is a link farm designed for SEO manipulation or to distribute further payloads. No scripts were extracted, but the primary attack pattern involves directing users to external, potentially malicious, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://accesoriosalmayor.com/images/userfiles/file/74353981744.pdf In PDF document text
    • http://thankschicken.com/uploads/files/94348217070.pdfIn PDF document text
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098d1d16afd8---labogudipevi.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/naxakovisiwebila.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/mfs346c9rkcjts1bqghefrrfrg/xasiperugi.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/nefuso.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160883710dee77---58113741777.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160942d0dbfdf4---34005185583.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606eb2b076ff6---69058993516.pdfIn PDF document text
    • http://usateatop.com/_upload/files/85698880210.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b5135393fa7---76848138367.pdfIn PDF document text
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/cbc5145fe93201d5ba19c5ffecaba8f6/birovumosupuju.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/roljf2h8ik5pmkdckl24rdtepi/17444458713.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/88913d1ad00fe3ead859d202fc2a6e40/4852015425.pdfIn PDF document text
    • http://stevis.cz/files/file/88809407042.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/21458400487.pdfIn PDF document text
    • http://wingprocess.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pududit.pdfIn PDF document text
    • https://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/000b64c1e50098731fa1ccf013f61f95/fijaxalazekatefapagos.pdfIn PDF document text
    • https://www.ergunaygoren.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d0e05ca52e---xotirusiluxepeb.pdfIn PDF document text
    • http://daotaoyduoc.org/wp-content/plugins/super-forms/uploads/php/files/7mecs1b67v4fuuuvf39lk0oiq7/40186440777.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/81kddrsju8sl7iceae6unug2e0/tasulorifizanux.pdfIn PDF document text
    • http://gadkowski.pl/repository/filemanager/file/59652413079.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=importance+of+fasting+in+the+biblePDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000119b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119B7 17044 bytes
SHA-256: 2b6dee5c5fa2524786162f6bb908df740539495efa9ff261e641455e64f42eb7
font_01_sfnt_off0001460d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1460D 11016 bytes
SHA-256: 34a63a2049d72c8c35620d72ecd0bd436db6a919f73ee9bf7d5d6d016b7b215c
font_02_sfnt_off00015f36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15F36 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1