Malicious PDF — malware analysis report

Static analysis result for SHA-256 871bf7c3668ccd3c…

MALICIOUS

PDF

114.8 KB Created: 2021-09-06 06:56:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 5bc9563adefe1a032889260d3b9336f4 SHA-1: b2f2fd644cc0a4f89c56ca162261976da6704f01 SHA-256: 871bf7c3668ccd3c83e84c5a66db60e8f863f24a6725f85bbe2f3ee6274121d3
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm, including links to compromised CMS uploads. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 https://red-adlay.com/upload/files/48327580236.pdf In PDF document text
    • https://aljuboori.com/userfiles/files/81677689914.pdfIn PDF document text
    • http://foto-klub.dk/userfiles/file/gikisixapiwosoj.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e4ea733f251---72400032185.pdfIn PDF document text
    • http://argyler.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607510a240a86---11576954658.pdfIn PDF document text
    • http://reicar.dk/userfiles/file/94991722012.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/f46d328a701da5a6da82737e092a11a0/judixu.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/viteqacv1vogdrrkp4m8saipl1/61020978663.pdfIn PDF document text
    • https://smartbrand.ro/mm/file/nonujuwarodelefora.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/161353ac77c9bb---80361415445.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee62b285c8---66440592720.pdfIn PDF document text
    • http://yuqiaohome.com/uploads/files/202108151729124195.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/29547602374.pdfIn PDF document text
    • https://durgabas.coop.np/ckfinder/userfiles/files/63332148416.pdfIn PDF document text
    • https://bientannamhuy.com/wp-content/uploads/files/10261410496.pdfIn PDF document text
    • http://eastmoorclassof1970.com/clients/4/43/4343e427eb1b0a0668350338a4d6b623/File/49185118591.pdfIn PDF document text
    • http://spoilersmensgolfclub.com/clients/865201/File/josesexewem.pdfIn PDF document text
    • http://viermaalh.nl/Bottesteyn/Site/afbeeldingen/file/bikotuzawudone.pdfIn PDF document text
    • http://ankurgroups.com/userfiles/file/31704773114.pdfIn PDF document text
    • http://quadocdao.vn/uploads/files/43764332883.pdfIn PDF document text
    • https://badoza.net/userfiles/file/kelarelezedojegabejigevi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=spectrum+math+grade+7+worksheetsPDF 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_off0001561e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1561E 20024 bytes
SHA-256: 17c23b352c1b1ede234ddb8c8cb1e4938d16f8430a7452c3a46eb2f7f36ef6a0
font_01_sfnt_off000189db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x189DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001a1f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A1F2 11120 bytes
SHA-256: ea745c559bbfedb9e20f8ea6916cb272d972ef672581ae5624604628a089195e