Malicious PDF — malware analysis report

Static analysis result for SHA-256 31c40e9f33e2efae…

MALICIOUS

PDF

90.4 KB Created: 2021-09-08 00:43:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 36082e4b9bc86e42dd2e11b0700b5ad7 SHA-1: cb08174b12c85ddbcd11709ac65cf7184d94a1b9 SHA-256: 31c40e9f33e2efae7779155fd8eed8b42c671c0ed58049a80d0c18e382dc2f8b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution lure, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://idd.no/ckfinder/userfiles/files/96335944224.pdf
    • http://radio-salsa.fr/php/rs/filesupload/file/96204238394.pdf
    • https://www.notusweb.com.br/ckeditor/ckfinder/userfiles/files/penofubodibu.pdf
    • http://royalrep.com/userfiles/files/nisigezezonexalutikaguwo.pdf
    • http://driver-jazda.pl/upload/file/ronenim.pdf
    • https://stormester.no/files/file/92420423697.pdf
    • https://mvmdigital.gr/files/files/tomupiwekokujinivosexani.pdf
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1609f38b6c8cca---38169148366.pdf
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/f37851deda94c1600aefeda2a119fdf7/gipedaxu.pdf
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/f091bff0f8c9836a62a3428c155c4b03/tugemetafafil.pdf
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/6g2uv4q7pvai5udjc2aac9ne23/ziguzotapetoj.pdf
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a7c30da6cf4---84629922526.pdf
    • http://dianacb.cz/userfiles/file/lopopezetuxazumej.pdf
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f47081d4f62---rowiji.pdf
    • https://emmaushuis.org/pages/9229429713.pdf
    • https://whatproperty.ng/ckfinder/userfiles/files/jatilivawapulunefavad.pdf
    • https://nexusmediation.nl/files/budenabuzetinutefebamel.pdf
    • http://www.findvoters.com/userfiles/file/96306801540.pdf
    • https://chv.vn/userfiles/file/66442079994.pdf
    • http://folientastaturen.pl/_data/file/guzemi.pdf
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/059f6dc3aaa467e3800c735077d040aa/zireranefipun.pdf
    • http://world-system-packet.com/userfiles/file/23099657694.pdf
    • http://alrehabourhome.com/userfiles/files/3749354635.pdf
    • https://kitapkaplama.com/upload/ckfinder/files/mitetolulagunijux.pdf
    • http://mbjarrahi.com/UploadedFiles/New/file/9561697972.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=analytical+writing+gre+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000faea.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFAEA 16792 bytes
font_01_sfnt_off000112fc.bin
d3f5e8391d9418ac5c1c53a5a3f0785b6df442a87400c8349bc603ae44bd1ca6
pdf-font-stream PDF embedded font (sfnt) at offset 0x112FC 18440 bytes
font_02_sfnt_off000143ac.bin
9b13677cc40539ee7311ee90e42abfe970d9e7e496dd4c881398b0f2dd1a2f37
pdf-font-stream PDF embedded font (sfnt) at offset 0x143AC 10688 bytes