Malicious PDF — malware analysis report

Static analysis result for SHA-256 33c3dab3c0831699…

MALICIOUS

PDF

86.6 KB Created: 2021-09-19 14:30:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 8f5e6ef0827a58497ec4fa0c20273a82 SHA-1: bffb86756d9b9906857eed73dd1cb65b59c5df66 SHA-256: 33c3dab3c0831699bc1382752f5f82bd3f64ea720c0c0b31bf0ade7569ccfdc4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 6

  • 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.
  • 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 http://sinocelltech.com/filespath/files/20210916225749.pdf In PDF document text
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/00cf6b65164938f3524f22105173c380/zajobatekuxiv.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f0815d15a4---bomazawinogakezixewosor.pdfIn PDF document text
    • http://achilleferolla.it/userfiles/files/boxopalevi.pdfIn PDF document text
    • http://klasykarozrywki.pl/public/images/fck/file/18798896209.pdfIn PDF document text
    • http://africalegal.nl/userfiles/file/86040425547.pdfIn PDF document text
    • http://diennuocdanang.com/uploads/image/files/57838499139.pdfIn PDF document text
    • https://amt-alarmy.pl/userfiles/file/pozijuvamemitefojebowonad.pdfIn PDF document text
    • http://uralteplostroy.ru/content/file/fafisuref.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16146ec3378890---37957238834.pdfIn PDF document text
    • http://myshopgroup.com/userfiles/files/85156874318.pdfIn PDF document text
    • http://www.veslovani-vsb.cz/soubory/file/80016976385.pdfIn PDF document text
    • https://inoxquochoang.com/app/webroot/files/images/pages/files/92114258608.pdfIn PDF document text
    • https://textolinguisticsolutions.com/upload/editor/file/devovimubakasufubi.pdfIn PDF document text
    • https://clubesolbra.com/uploads/files/71616416134.pdfIn PDF document text
    • https://satesayap.com/contents/files/48800704397.pdfIn PDF document text
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/0490qp80ou60pr8e2oioimtnsl/roxilavubabudozuvekisa.pdfIn PDF document text
    • https://megatekspb.ru/sites/default/files/uploads/99052851315.pdfIn PDF document text
    • https://dailyiat.com/html_upload/file/26624277937.pdfIn PDF document text
    • https://hainutedecopii.eu/ckfinder/userfiles/files/65406031232.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613d640b91e99---tavalaxuxiwaminimukopodax.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=amazing+offline+gamesPDF 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_off0000f0e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0E2 10400 bytes
SHA-256: a9d6f663a6fe81b22a5b3f035af3cd0eba237084df3f96cf410be6a7cc9c5a9b
font_01_sfnt_off0001086b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1086B 17168 bytes
SHA-256: 809ffd6c4add5bc69c9da1f468d6818c5ca69ad8d733387ddbd4e0d5beecd37b
font_02_sfnt_off00013508.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13508 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1