Malicious PDF — malware analysis report

Static analysis result for SHA-256 421b4c8ee73509c8…

MALICIOUS

PDF

95.4 KB Created: 2021-09-06 12:35:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a4be914a6992c904dfd983c8cba1f696 SHA-1: 5e86d579abee146722a4ee237a759ec91c96c2ee SHA-256: 421b4c8ee73509c80f6e9d7143db7cc7d37be0e4431d08dcbe697c6c43298523
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9897

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://baigeleather.com/userfiles/file/zopumerosezuxixuxabomaj.pdf In PDF document text
    • https://topconta.ro/userfiles/file/kewoxiwaxomokezoxalumigiv.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16106ac05b4eda---81449857932.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afa795e5bc7---datifagaxumepovagevu.pdfIn PDF document text
    • http://best-infosystems.com/userfiles/file/xegivowifo.pdfIn PDF document text
    • http://studioambienteterritorio.it/userfiles/files/dakubuwosum.pdfIn PDF document text
    • https://bestcoloringpages.com/userfiles/file/13403489445.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608a7374ce7bb---13796697017.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/3817144cb36f6e3d6a82d7575cdbd970/46579375958.pdfIn PDF document text
    • http://nature-revive.org/files/file/86503492537.pdfIn PDF document text
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/g3c3ebgsfq18nubt7rdcphve80/23287918192.pdfIn PDF document text
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/94d731198cc4dc906f2a598bf2d74369/86440858622.pdfIn PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e80c600dfe---25901299047.pdfIn PDF document text
    • http://luxmeterthai.com/ckfinder/userfiles/files/xafoxomugi.pdfIn PDF document text
    • https://armagedonspedycja.pl/files/file/37379738918.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160780dc34e4bb---57378842236.pdfIn PDF document text
    • http://assessmentinsight.com/ckfinder/userfiles/files/71917978760.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/16082d438a4d10---82161146449.pdfIn PDF document text
    • https://namdolove.com/FileData/ckfinder/files/20210528_C79A4BE3C89744DE.pdfIn PDF document text
    • https://clumba-indoor.ru/files/files/57523892393.pdfIn PDF document text
    • https://useoneconvo.com/wp-content/plugins/super-forms/uploads/php/files/dc37867cce13f66c35ab7cf49ff7c5ee/mepupifid.pdfIn PDF document text
    • https://www.mds-horizons.com/upload/files/pofawegoko.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/r43o8vfnqj0ie3g08dncg1scic/95578435919.pdfIn PDF document text
    • http://ac-kenigsberg.ru/files/file/9045795545.pdfIn PDF document text
    • http://masan315.net/board/imagefile/file/6617651916.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16084e6728159a---95628749197.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=finance+islamique+d%C3%A9finition+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_off000105ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105AC 11056 bytes
SHA-256: 3e4789912057097f5a709dc976cfce0fb5fcce9f51b456cc5952783c4aeef571
font_01_sfnt_off00011ed8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ED8 21636 bytes
SHA-256: a045416db7e1d032b4edffda4958ba8bfcaa26ba7f169ebde85360f8db9acca3
font_02_sfnt_off00015590.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15590 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1