Malicious PDF — malware analysis report

Static analysis result for SHA-256 3bf71a0cc08aed42…

MALICIOUS

PDF

86.5 KB Created: 2021-07-15 23:25:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 086425c38d04d3f10b1244d0e0495ac4 SHA-1: 779a002b3a312987e67f6c01a3f6fc3ee8886ccc SHA-256: 3bf71a0cc08aed42a207da358430618223415d1216f8521bd4adad00ae4f5b6a
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://4bx.pl/public/file/51211134509.pdf In PDF document text
    • https://citytrafik.nu/images/file/21744311113.pdfIn PDF document text
    • https://louvre.lv/res/wysiwyg/file/20515603749.pdfIn PDF document text
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/7a1hlciiov54bfhc8p32eoj1e8/memozelupamugidijadapuvu.pdfIn PDF document text
    • https://abe-rdc.com/userfiles/file/11699150201.pdfIn PDF document text
    • https://www.micron21.com/application/third_party/ckfinder/userfiles/files/fijosefipezuzezadizu.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084366ba85f3---wuxupigomudazeporife.pdfIn PDF document text
    • https://uppersanduskyrotary.com/cms/files/File/47854941840.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609ada601458c---60518442034.pdfIn PDF document text
    • https://amrapalispot.com/userfiles/file/75613855496.pdfIn PDF document text
    • http://sun-green.be/ckfinder/userfiles/files/57156466317.pdfIn PDF document text
    • https://majorsagilekvaros.hu/uploads/file/befigul.pdfIn PDF document text
    • https://kurtoglumob.com/upload/file/22468912784.pdfIn PDF document text
    • http://eviljoy.com/UserFiles/File/94544895442.pdfIn PDF document text
    • https://leo-translate.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1607451bbd5fc8---50836509147.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082ba0a53dd0---wewokapilizipewetowa.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608f81a5580c7---xamogezalokapaja.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f30ba2bfeb---51191885686.pdfIn PDF document text
    • http://usmleworkout.com/files/file/gofixapidawepobo.pdfIn PDF document text
    • http://fotografiafrancescosomma.com/userfiles/files/99823583775.pdfIn PDF document text
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a8727ce08b---27389609298.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/7e780d0bffe362fa739b6e57873a3f97/8606264890.pdfIn PDF document text
    • http://cuadepthanglong.com/images/ckeditor/files/rivojawabadovafosire.pdfIn PDF document text
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac67f2d1eb5---mokatu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=pdf+online+text+editorPDF 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_off0000ef6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF6A 10120 bytes
SHA-256: e5bf5529cd945cd056ae465802fad62317586909ccf0c34d996fc608471b9ca2
font_01_sfnt_off00010613.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10613 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E25 17312 bytes
SHA-256: 9603b558f269775b2413f722623e19d8a0685b2e2979037f0547d2092315573e