Malicious PDF — malware analysis report

Static analysis result for SHA-256 97ebb7209da1137a…

MALICIOUS

PDF

98.1 KB Created: 2021-09-07 22:47:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: a9a68feaa450e215435300fda73301f5 SHA-1: f378b3cb296384d3fb5506c39d77a51fe441d9a4 SHA-256: 97ebb7209da1137a4544e99e7d9c22842617ba0053f855cc760a55d5eea873da
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://elearning-chemistry.ro/userfiles/file/81157699291.pdf In PDF document text
    • https://vico-inmobiliaria.com/ckfinder/userfiles/files/69266027545.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/16124f150dbd18---7559019139.pdfIn PDF document text
    • http://www.chatanakonci.cz/userfiles/file/sikowufapusowufovi.pdfIn PDF document text
    • https://nhaccugiare24h.com/uploads/userfiles/file/sadig.pdfIn PDF document text
    • https://iaido-iaijutsu.ru/userfiles_exc/vigukirat.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c6cdd415b5c---gufipedetijanol.pdfIn PDF document text
    • https://saigonservices.vn/images/uploads/files/vudevinupupakirugu.pdfIn PDF document text
    • http://agro-partner.com/Image/files/95837101102.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b9c9b61e026---499750429.pdfIn PDF document text
    • http://runningrhinelanderrabbitry.com/clients/875187/File/kovatiposiwage.pdfIn PDF document text
    • http://educasters.co/ckfinder/userfiles/files/81922278650.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16109fb450a694---5953355916.pdfIn PDF document text
    • http://thaiboxes.com/piceditor/file/mewusadupebegigopif.pdfIn PDF document text
    • https://infiniteprospects.com/FCKeditor/file/64377768911.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/41c5acc52a7615a93152689bb11445ee/4345209848.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a636a27977---megegebezojolutop.pdfIn PDF document text
    • http://elitvorota.ru/f/file/gotusitatuzixopuxaregadag.pdfIn PDF document text
    • https://tomas-music.com/contents//files/tevozorisibaxalakuvajafuf.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b98a38a24c2---rejabuwalaveb.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/475abc0d9112105a0e02fa4b86a0175c/naxiburudixeso.pdfIn PDF document text
    • http://veterina-hrib.cz/user-uploads/files/81631850259.pdfIn PDF document text
    • https://aimtronu.org/userfiles/file/wapamarajanafejopenudan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=ortografia+de+la+lengua+espa%C3%B1ola+2010+pdf+completoPDF 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_off000110cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110CF 20088 bytes
SHA-256: 18653450e031ce005660eee1bc4a810f20464576640a126bac4fe178296fcd73
font_01_sfnt_off0001449a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1449A 11588 bytes
SHA-256: 7f8b578e66564425a98f956ac54b98f116d18cc6dac230af2a6a20a120a4fd99
font_02_sfnt_off00015fbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15FBC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1