Malicious PDF — malware analysis report

Static analysis result for SHA-256 441e61a8bf25b72c…

MALICIOUS

PDF

80.0 KB Created: 2021-09-21 22:33:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 013f9eb43b57d2e817befbbcb5e90dba SHA-1: ef005897c8cb66d539d008a693a7a5a3f513eb45 SHA-256: 441e61a8bf25b72c439cbe4805a5159fc4aa3765273c688322aceb557ff03ed4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised websites or disposable hosting, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs are consistent with techniques used to redirect users to malicious sites, often as part of a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://wastran.ru/uplcv?utm_term=english+file+4th+edition+upper+intermediate+teacher%27s+book+pdf PDF link annotation
    • http://baove247.org/upload/files/26540583240.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/161444b5886e6c---59631219823.pdfIn PDF document text
    • http://explosivedevices.ru/media/file/lodemutedenawo.pdfIn PDF document text
    • https://farmacieitaliane.com/documenti/file/14932162982.pdfIn PDF document text
    • http://jmvlpslimited.com/ci/userfiles/files/zavezubefenejileva.pdfIn PDF document text
    • http://etenindex.nl/images/uploads/gebin.pdfIn PDF document text
    • http://kimkhimientrung.com/uploads/image/files/pixop.pdfIn PDF document text
    • https://marblobathware.com/app/webroot/img/files/67867243592.pdfIn PDF document text
    • https://asiapharma.la/files/files/nesabuzepul.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/16146575b740dc---25648820039.pdfIn PDF document text
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/49964982667.pdfIn PDF document text
    • http://ocvitlucky.com/vietkiendo/upload/file/wevugopijenilesumowanu.pdfIn PDF document text
    • https://basealimentare.it/webroot/files/fck_uploads/File/wuruxafozinumuri.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/1134bf15d351b36097310da7ffcedcba/papesatawu.pdfIn PDF document text
    • https://basalyemek.com/ckfinder/userfiles/files/soralivix.pdfIn PDF document text
    • http://hocomesun.com/upload/67674356438.pdfIn PDF document text
    • http://ndt-ultratech.com/files/77871832096.pdfIn PDF document text
    • http://short-story.ru/upload/file/48460391037.pdfIn PDF document text
    • https://aljazeerahpetroleum.ae/userfiles/files/zubixedadeweneworu.pdfIn PDF document text
    • http://www.plan.msu.ac.th/ckfinder/userfiles/files/nukozenewijuwaluzerupiki.pdfIn PDF document text
    • https://ruedi-leuthold.com/userfiles/files/69017860171.pdfIn PDF document text
    • https://vicareyou.com/userfiles/file/menugu.pdfIn PDF document text
    • http://ros-audit.com/i/up/file/63430630805.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_off0000cf3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF3A 18356 bytes
SHA-256: 6ae64c5164f95549d1d9fcf5df52cf93e8376b76fcc4d940016f051c4cd35579
font_01_sfnt_off0000ff1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF1F 11496 bytes
SHA-256: 27aff709c5cfb588ff3bc9b466ae744e1e1a31e1464cf3656ddab699085f586a
font_02_sfnt_off000119cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119CB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1