Malicious PDF — malware analysis report

Static analysis result for SHA-256 5acebc2c81404243…

MALICIOUS

PDF

75.6 KB Created: 2021-10-10 15:26:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 0d6010ca0ef9d32983a5606ff07b6308 SHA-1: 930f976f47047c398d15c77b8e1aed5179ea6419 SHA-256: 5acebc2c81404243e8fe4f1eff0f814dd0aed106f0cf13b3ded81d7d1d3256c5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm or redirection mechanism. The presence of embedded URLs and the nature of the heuristics indicate that this PDF is likely used to direct users to malicious websites, potentially for phishing or to download further malware. No scripts were extracted, but the PDF structure and URL patterns are strongly indicative of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 https://laborke.ru/uplcv?utm_term=the+g+clef PDF link annotation
    • https://samuelben-horin.com/userfiles/file/foruzifikiwalepubobebebub.pdfIn PDF document text
    • https://riondene.ch/img/uploads/file/3577231973.pdfIn PDF document text
    • https://ecoledesgourmets.com/userfiles/file/fepawozufoketuxe.pdfIn PDF document text
    • http://thebankcardservices.com/uploads/files/19871156020.pdfIn PDF document text
    • https://activepymes.com/pub/file/51476416709.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/65773522483.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613f65a371357---68372387880.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/87kt6ulo5fm23j5njff6rf7rt5/69059332499.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f4bfdc3517---73946524221.pdfIn PDF document text
    • http://vekosgroup.ru/userfiles/file/biriluman.pdfIn PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16130e92f25826---tirejiwuzofagonese.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///20533664579.pdfIn PDF document text
    • http://ahjygjg.com/upload_fck/file/2021-9-22/20210922155503712553.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/722ff54c24862d69ed1111bb86cbb645/73220644332.pdfIn PDF document text
    • http://banghetretunhien.com/media/ftp/file/36136818820.pdfIn PDF document text
    • http://aftp.bg/userfiles/file/rutunuturuxovebonefitula.pdfIn PDF document text
    • http://mzch.pl/userfiles/file/gopunixarerunovit.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/16139a1aea7cd3---pakisumodutikiferasesatud.pdfIn PDF document text
    • http://rideabikenews.com/user_img/files/jizufaxuwe.pdfIn PDF document text
    • https://enilubricantvn.hoakhanh.vn/uploads/image/files/warox.pdfIn PDF document text
    • http://union.travel/ckfinder/userfiles/files/69765293154.pdfIn PDF document text
    • http://www.szphotar.com/admin/img/files/52411578912.pdfIn PDF document text
    • 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_off0000c471.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC471 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dc87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC87 9732 bytes
SHA-256: 0289ee6a26252d6f383a313fd47c3247ba3f46a4bfb0d38b217c130f18c6d1b9
font_02_sfnt_off0000f1e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1E0 18516 bytes
SHA-256: d440d67f2ed31488a9dfc881c687051f98e94e48cc715a2f42c171a48e41b82f