Malicious PDF — malware analysis report

Static analysis result for SHA-256 8812eb83b0ba5677…

MALICIOUS

PDF

72.7 KB Created: 2021-09-19 11:53:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 785d77f4cdabd20c6f977b79533b73cc SHA-1: ec925ef22baccfb1c5802a38132477733c9a551f SHA-256: 8812eb83b0ba56777a00945846b1e4fbdcf3ae59d8336f8a103a4b8f2d950dd0
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous external URLs, many hosted on compromised or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, but the structure suggests it's designed to lure users to malicious content via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://dgkno.cn/upload/75609510603.pdf In PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c54babe840---10948103619.pdfIn PDF document text
    • http://vaynhe.com/upload/files/94914303462.pdfIn PDF document text
    • https://bosingels.nl/ckfinder/userfiles/files/ludux.pdfIn PDF document text
    • http://donahoelawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fuwitamilavefifi.pdfIn PDF document text
    • https://yodobashi-church.com/3645574869.pdfIn PDF document text
    • http://araratmebel.ru/img/file/bibusojilip.pdfIn PDF document text
    • https://mmtours.si/uploads/zojofar.pdfIn PDF document text
    • http://ledspectrumthai.com/ckfinder/userfiles/files/wakasamikizifupe.pdfIn PDF document text
    • http://prabashproperties.com/ckfinder/userfiles/files/80637536098.pdfIn PDF document text
    • http://tw-tms.com/uploadpic/xw/files/58527144169.pdfIn PDF document text
    • http://noithatdangcap.vn/app/webroot/uploads/files/rusotumifozuxanadubiz.pdfIn PDF document text
    • http://angel-conference.org/upload_fck/file/2021-9-6/20210906070859443420.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-1/20210901091758365929.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a6f3d18868---funuru.pdfIn PDF document text
    • http://sor1310.com/userfiles/file/43305550791.pdfIn PDF document text
    • https://tonerihned.cz/userfiles/file/17561649445.pdfIn PDF document text
    • http://privateeducation.sg/verzsape/demo/upload/admin/files/tevajiv.pdfIn PDF document text
    • https://supermagnum-bg.com/ckfinder/userfiles/files/85171922601.pdfIn PDF document text
    • http://fese.in/ienupdimages/images/files/dadilisez.pdfIn PDF document text
    • https://beautifullifeuk.com/wp-content/plugins/super-forms/uploads/php/files/5df96521b8eae833f1dc85cfeaf03c52/jevadokapexudaxesevinamim.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=undertale+undyne+the+undying+simulatorPDF 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_off0000b921.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB921 16564 bytes
SHA-256: 8e6410c7d0508d2c9a42cf4ac20be5f6e5b31bb99bcc1008a38d7c1cd234447d
font_01_sfnt_off0000e411.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE411 10916 bytes
SHA-256: 3413c3d61a3fe49c25e64fa4412f6f4424f308b1a8a2eeb39157bb0433204754
font_02_sfnt_off0000fcee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCEE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1