Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfb79ffdb6823c5f…

MALICIOUS

PDF

77.1 KB Created: 2021-09-16 21:33:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: af8d9bf01dc50dbabce63c8a9be1466f SHA-1: b9c140e1b6d621e1a8c876d4baf7112c9254acb4 SHA-256: cfb79ffdb6823c5fa160df9970d100988905c38edc99d28f428868f12fd2e249
146 Risk Score

Malware Insights

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

The sample was flagged by ML classifiers and ClamAV as malicious, with specific heuristics indicating it's a phishing lure designed to trick users into calling a fraudulent phone number. While no scripts were directly extracted, the PDF structure and embedded URLs suggest it's part of a phishing campaign, likely exploiting a vulnerability to execute further malicious actions. The presence of numerous embedded URLs, many pointing to potentially compromised sites, reinforces the phishing and potential exploitation vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://www.kowel.com/ckfinder/userfiles/files/1631816664.pdf In PDF document text
    • https://wojczak.pl/userfiles/file/lizufoki.pdfIn PDF document text
    • http://sbairs.com/datas/files/lasajada.pdfIn PDF document text
    • https://fanaf.org/article_ressources/file/5377308075.pdfIn PDF document text
    • http://www.motionmantra.com/userfiles/files/11988270121.pdfIn PDF document text
    • http://xn--80adpfaaeictf0c6c7i.xn--p1ai/public/file/semibupakenirokabenowi.pdfIn PDF document text
    • http://www.jucadent.es/ckfinder/userfiles/files/saribedadeg.pdfIn PDF document text
    • http://zaintik.org/files/galeria/files/kutatataxosisikuxo.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612fab4b4e722---54957637926.pdfIn PDF document text
    • http://gma.ge/admin/ckeditor/ckfinder/userfiles/files/35580862703.pdfIn PDF document text
    • http://goopenapp.com/uploads/files/7309051381.pdfIn PDF document text
    • http://skncn.com/u/files/543772722.pdfIn PDF document text
    • http://n-production.com/upload/fckeditor/file/nowikesazebebanagi.pdfIn PDF document text
    • https://safecampus.in/cmsCart/upload/file/16585891512.pdfIn PDF document text
    • http://jrecchina.com/ckeditor/ckfinder/userfiles/files/pijedepotebidegomoz.pdfIn PDF document text
    • https://transilvaniafishing.ro/app/webroot/files/userfiles/files/79537530309.pdfIn PDF document text
    • https://mariapolis.es/ckfinder/userfiles/files/witodenidex.pdfIn PDF document text
    • http://christopherspubandgrille.com/userfiles/files/migoriremeluruposizar.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/4994445371.pdfIn PDF document text
    • https://etevent.itweald.com/uploads/files/6138df39ea32c.pdfIn PDF document text
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/37d0eb8c4b728263faebf935a8d9a24b/11705372935.pdfIn PDF document text
    • http://costruzionibulagna.it/userfiles/files/xepewuvagisufug.pdfIn PDF document text
    • http://brandnewgoods.net/userfiles/file/68803958445.pdfIn PDF document text
    • https://phu-komplex.pl/pliki/file/14354252985.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=suzuki+violin+volume+11+pdfPDF 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_off0000c490.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC490 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dca2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCA2 18988 bytes
SHA-256: 11d4b9032d901960133f5e8b59c6101c40b987ff0c7dc8c78ad5a3bdf6eaedb4
font_02_sfnt_off00010eeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EEB 10576 bytes
SHA-256: 9e341e9ae44ce0c45248aeac52a908d271709e820a06f5de407280319737b203