Malicious PDF — malware analysis report

Static analysis result for SHA-256 36d65be6da31463b…

MALICIOUS

PDF

75.7 KB Created: 2021-09-14 04:58:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7da63fa3490ae84122897ae5e9271362 SHA-1: feea3538942f426c90b6afd618b21b182dca2e7b SHA-256: 36d65be6da31463bb10840959dec49f8b8db7da9f8a98a554c43d8635373e6bf
116 Risk Score

Malware Insights

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

The PDF file contains numerous embedded links, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple PDF_URI heuristics confirms the malicious intent of linking to external resources. No scripts were extracted, and the document body was unreadable, so the primary attack vector appears to be the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 6

  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://curtain.jinware.com/upload/files/9422139641.pdf In PDF document text
    • http://autoklej.pl/app/webroot/media/files/timomobo.pdfIn PDF document text
    • http://beiwendq.com/data/attachment/file/gezotek.pdfIn PDF document text
    • http://kuhomania.ru/ckfinder/userfiles/files/36302669230.pdfIn PDF document text
    • http://79.170.40.182/boothtastic.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613480957df79---voloxujizesediwidaxexu.pdfPDF link annotation
    • http://malir-naterac.info/UserFiles/File/89866079671.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/16139aee1b745d---60035741836.pdfIn PDF document text
    • https://angelsolutions.ro/ckeditor/ckfinder/userfiles/files/81521654002.pdfIn PDF document text
    • https://gmnavarra.es/ckeditor/files/dotedomeniwewevesatuwa.pdfIn PDF document text
    • https://alummaswaja.com/yii/sdbalikpapan/home/images/upload/files/mitoxod.pdfIn PDF document text
    • http://geose.ru/userfiles/file/4697526183.pdfIn PDF document text
    • https://ispartaprefabrik.com/ckfinder/upload/files/98118424762.pdfIn PDF document text
    • http://yizhu580.com/ckfinder/userfiles/files/sulebila.pdfIn PDF document text
    • http://dvif.fr/userfiles/file/satakediropofizuxojadizon.pdfIn PDF document text
    • http://ascensionchina.com/userfiles/file/fanazotitaxuxixuxiduxevub.pdfIn PDF document text
    • http://studiovalentini.eu/userfiles/files/xilegifokebawoda.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131c6f10562e---22107046184.pdfIn PDF document text
    • https://m-isc.com/userfiles/file/vakizamiwujilulaluvimewum.pdfIn PDF document text
    • http://techcessgroups.com/userfiles/file/zosopa.pdfIn PDF document text
    • http://www.slappedtogether.com/editoruploadfiles/file/27725181768.pdfIn PDF document text
    • http://www.boldino-hotel.com/ckfinder/userfiles/files/xipijarobolononutexeg.pdfIn PDF document text
    • https://landtop.com/filespath/files/20210908230930.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fd1aa83210---fiseze.pdfIn PDF document text
    • https://tungafilm.com/dorceiys/ckfinder/userfiles/files/vaxupizuso.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=golf+clash+mod+apk+2020PDF 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_off0000c3f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3F7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dc09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC09 17236 bytes
SHA-256: 37593fc2064783fb2fd8940c19f0f298bdc5d1a93e0fa11519b151abc28344bb
font_02_sfnt_off000108d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108D6 10732 bytes
SHA-256: 55ff6c1e4f2ff21efd6b3ede50c66d554a2f0184d2f736aa8a45b0105af5c45a