Malicious PDF — malware analysis report

Static analysis result for SHA-256 5944cd5cb790496d…

MALICIOUS

PDF

106.4 KB Created: 2021-09-03 13:35:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: b0468885b65b8ebd2acfe8a8e6bb50ad SHA-1: bb87fdbdb52115b32e6a256f82a561ef0dcea48c SHA-256: 5944cd5cb790496d03a1874abebb8f0ff3446f900b5e48f0d45b0a860bec0173
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous PDF files hosted on various domains, several of which are identified as compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://aliceinformaticasrl.com/user/pages/kuzoverozabujorikijifef.pdf In PDF document text
    • http://getampedmag.com/ckfinder/userfiles/files/9941744995.pdfIn PDF document text
    • http://elm3rad.com/file/biruxotopufewaj.pdfIn PDF document text
    • http://fotobambagiotti.it/userfiles/files/54147586550.pdfIn PDF document text
    • http://www.pilonidalsinus.gen.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606c69e778de9---pitilisor.pdfIn PDF document text
    • http://titadoorbinhduong.com/upload/files/9274996587.pdfIn PDF document text
    • https://prawobrzeze.info/userfiles/file/mukarikodexope.pdfIn PDF document text
    • http://niszczeniewaw.pl/userfiles/file/zegerowufobijovoz.pdfIn PDF document text
    • http://inse.us/uploads/images//files/kaxozegasezokepowopegoja.pdfIn PDF document text
    • http://thesecurityguardunion.ca/userfiles/files/pawevakenovuvubezosepu.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/161089ea51fb9c---26277633843.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609282a59a549---94048000046.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16090f5b8eae28---joxeb.pdfIn PDF document text
    • https://www.e-oswiata.olesnica.pl/ckfinder/userfiles/files/fitolozupak.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/a6e59704e7519eb0907f0a3cb86aab54/jetamivegexibipinurisira.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d531c16ceb---pokezosixuzatu.pdfIn PDF document text
    • https://neksav.com/upload/ckfinder/files/notupunewusisefugev.pdfIn PDF document text
    • http://tpdw.pl/userfiles/file/dogoge.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/539c2ef2bf9a0551f1ddad760296c5a6/39973717705.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.com/filespath/files/20210810113108.pdfIn PDF document text
    • http://rts-3.ru/upload/files/29236959981.pdfIn PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/b2b832bfcba556462e97df5bbfbc2263/mipalodojin.pdfIn PDF document text
    • http://erfansari.ir/ckeditor/files/files/80669000564.pdfIn PDF document text
    • https://maxflowfans.com/userfiles/file/dolulizogepapudisalideda.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1610c1575e605f---mixexebo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=maharashtra+cooperative+housing+society+manual+in+marathiPDF 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_off000133bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133BC 20672 bytes
SHA-256: 5080be9386509ee0df585edfcda6c227cf83bb4223e761d4741334caabcaa72a
font_01_sfnt_off0001695d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1695D 11096 bytes
SHA-256: 24caeffec9faf7feaf91962564bc61f03066d030b422cc5008f832391b856dd8
font_02_sfnt_off0001831c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1831C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1