Malicious PDF — malware analysis report

Static analysis result for SHA-256 4428be17ff8a7cc2…

MALICIOUS

PDF

94.7 KB Created: 2021-07-25 08:58:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 6b8b4748ba8fca6015b9b47c8e73a3dc SHA-1: 2cff0930d614126f881a59500103911677fed3b8 SHA-256: 4428be17ff8a7cc22c3d84a33d79ab821c7044c65d891f3f170b9364afd9cc63
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ClamAV as 'Pdf.Phishing.Trojan' and an ML classifier indicated a high probability of maliciousness. Static analysis revealed numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The document body was unreadable, but the heuristic firings strongly indicate a phishing or redirection attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160790a6383563---69560993702.pdf In PDF document text
    • http://valsadindustries.com/userfiles/file/93102393218.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/2b5935453677799c34032603c4f2570e/80459249949.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a888c317406---suzabolovigobakug.pdfIn PDF document text
    • http://alpanelektrik.com/depo/sayfaresim/file/vofemilubodobiximosisi.pdfIn PDF document text
    • https://aldaserwis.pl/ckfinder/userfiles/files/laguzededoripolesotevere.pdfIn PDF document text
    • https://sgotomotiv.org/upload/files/senovaralotodekugowela.pdfIn PDF document text
    • http://travelport.pl/userfiles//file/zixerokijapobemezixodive.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a56c8dc5103---75203559653.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/00mfhj9q8d70h8lejha95vitu4/85561879333.pdfIn PDF document text
    • https://drsaman.com/files/jibekixid.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160ba21422e05b---44688399222.pdfIn PDF document text
    • http://ldbell1965.net/clients/85689/File/4470633888.pdfIn PDF document text
    • https://rpitrade.com/ckfinder/userfiles/files/96554788688.pdfIn PDF document text
    • https://thefertilizerequipment.com/d/files/vonedan.pdfIn PDF document text
    • http://soupworld.de/upload/file/ninuwililijavonijofome.pdfIn PDF document text
    • https://saint-florentin.charcutier-traiteur.fr/ckfinder/userfiles/files/rukorinevitikow.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16097f3fa2d543---34972812125.pdfIn PDF document text
    • http://www.rify.us/cms-uploads/files/47482329810.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16080d89a7492e---32285783579.pdfIn PDF document text
    • https://medsplus.us/admin/images/file/nugebobap.pdfIn PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8846b9a3fb---rojibaloz.pdfIn PDF document text
    • http://dhsclassof70.com/clients/d/d1/d13f49183e6b2ef720c1f353b43de0f2/File/xifisojugabugawuvipiwi.pdfIn PDF document text
    • http://immobilieninvestors.org/userfiles/file/86360122853.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=harry+potter+hedwig%27s+theme+notes+pianoPDF 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_off00010b7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B7E 11016 bytes
SHA-256: e959299f1276cbe33a41a106490b17e54780880fb9280a5d617627137588c60d
font_01_sfnt_off000124d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124D1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013ce3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CE3 17948 bytes
SHA-256: 20b7a5bafe355223b37d249e3768857a42b29ef4e91f75f28e98ce17ac9304c2