Malicious PDF — malware analysis report

Static analysis result for SHA-256 51f783d7b625d049…

MALICIOUS

PDF

69.3 KB Created: 2021-09-16 02:21:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 031f19b810ffb42870b8f45c284b6b56 SHA-1: 214e5d7b15b69091a4ec3e5cacc0d75ae7f38b45 SHA-256: 51f783d7b625d04904c03920919ab7edd6fb91b90e66519efa273c41ea3d4095
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that form a link farm, with many pointing to compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. Although no scripts were extracted, the PDF structure and URL patterns suggest it's designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://archism.ru/uplcv?utm_term=wwe+mayhem+apk+download PDF link annotation
    • http://fruitvita.com/files/files/74406216832.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137bd0a49c1b---kexenabudotovozilevuxes.pdfIn PDF document text
    • https://tyeetomsfishing.com/userfiles/file/73795276369.pdfIn PDF document text
    • http://world-housing.jp/ckfinder/userfiles/files/84878497065.pdfIn PDF document text
    • http://zvezda-rostov.ru/ckfinder/userfiles/files/12809314588.pdfIn PDF document text
    • http://ntouioc.ntou.edu.tw/ckfinder/userfiles/files/wijuwujagig.pdfIn PDF document text
    • https://actorconseil.com/files/file/jifowepomegobagax.pdfIn PDF document text
    • http://c-six.it/userfiles/files/90429347762.pdfIn PDF document text
    • http://gt-outillages.fr/ressource/site-image/files/70291305887.pdfIn PDF document text
    • http://hai-bi.com/uploads/files/202109141930173057.pdfIn PDF document text
    • https://j26clean.com/upload/files/60947663763.pdfIn PDF document text
    • http://casaperferiesantamariagoretti.com/writable/public/userfiles/file/kalenodipovedenifodubine.pdfIn PDF document text
    • http://oticonshop.net/ckfinder/userfiles/files/lizomexavigijanemo.pdfIn PDF document text
    • http://mirsistem.com/depo/sayfaresim/file/85022695655.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/161426a9b8272d---81529620078.pdfIn PDF document text
    • https://nikunjfoundation.org/ckfinder/userfiles/files/dojopulewevu.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bc45a825b8---96182625670.pdfIn PDF document text
    • https://stop-remont.ru/ckfinder/userfiles/files/42673889701.pdfIn PDF document text
    • http://psychologkmalinowska.pl/ckfinder/userfiles/files/bipefen.pdfIn PDF document text
    • http://kaies.net/upfiles/file/59083333262.pdfIn PDF document text
    • https://bosingels.nl/ckfinder/userfiles/files/mesepularixofanupobitoje.pdfIn PDF document text
    • https://12shio3.com/contents/files/zegomowamisiduxel.pdfIn PDF document text
    • http://realtor-madrid.com/uploades/fckeditorfile/xenufosodiwolodamig.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_off0000b1db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c9ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9ED 15108 bytes
SHA-256: 0527063e0e2a74579eea3dd687709fc5c055c139367b4c27b75a38147f080f10
font_02_sfnt_off0000f03e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF03E 10484 bytes
SHA-256: ee86bef166b641329fafaf556b52eb961e434d4347ff22c35e277420fa58e201