Malicious PDF — malware analysis report

Static analysis result for SHA-256 a507cde34de3a97e…

MALICIOUS

PDF

92.8 KB Created: 2021-08-13 05:09:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 9cf6ac3017e5494ff9cc59d6a078ddc4 SHA-1: af3fd49dac2b6faa0c4d16c768deec6da1d979b7 SHA-256: a507cde34de3a97ea3a81095d7ff25aa81d6ac896cd6e8ca4969e8addfab2a5a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting, likely to redirect users to malicious content. The document body is unreadable binary data, suggesting it's not intended for direct user consumption but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://vcvscr.cz/www/www/fckphotos/file/9063282542.pdf In PDF document text
    • http://saydersan.com/firma/files/fafevipukewawuvome.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/16094dc65bc864---26774380366.pdfIn PDF document text
    • http://likebarcode.com/image/files/20210811_212751.pdfIn PDF document text
    • http://phyllisrubensteinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/furasaruxupisesabuken.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/1610c40e0caf05---kigudasigamivejasegon.pdfIn PDF document text
    • https://propactionvehiclesuk.tv/userfiles/files/20350270097.pdfIn PDF document text
    • http://klubbelgickychobrov.sk/editor_uploads/files/73922585364.pdfIn PDF document text
    • https://go2germany.ru/files/file/zuziripapibu.pdfIn PDF document text
    • http://musthighschool.mn/ckfinder/userfiles/files/vogesawakexididubedo.pdfIn PDF document text
    • http://apnorajasthan.net/userfiles/file/63977013069.pdfIn PDF document text
    • http://engroupe.ca/aym_image/files/safalitujaguvowawibonak.pdfIn PDF document text
    • https://alasclub.gr/neuro/ckfinder/userfiles/files/wegemuf.pdfIn PDF document text
    • http://cnhhgj.com/upfiles/userfiles/file/8760408824.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/b81cer3rmtgm2gjpuj6u6eikq7/44982736730.pdfIn PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/2a53ae788a39ba076134cf592c21a072/nupufozexokopobusapi.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16107d3d313e05---7707011266.pdfIn PDF document text
    • https://cfbadalona.net/ckdata/files/43821845992.pdfIn PDF document text
    • http://scamps.biz/userfiles/file/modig.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/d32bc8c190b7e66ebaa9eae7f689c2f8/birabi.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/16087b467b36e5---91282864201.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=glutamato+monosodico+y+cancer+pdfPDF 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_off000103a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103A1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011bb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BB3 18032 bytes
SHA-256: eb2141784da3eb6ee6d8453d710a35a367cb1a0f5154303cd3ae490fb7675a36
font_02_sfnt_off0001493f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1493F 11032 bytes
SHA-256: cf7f27d02c8d3714ec1a620a81da7ab30572c72281cf3ced840c30da15f181b4