Malicious PDF — malware analysis report

Static analysis result for SHA-256 c31ccdec154d1fad…

MALICIOUS

PDF

85.5 KB Created: 2021-09-02 18:50:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 01e411ff87f4b1d061ddadf0c37d6255 SHA-1: cf8d77a1a99152e5b3fac788eaabdd3e708c1fd2 SHA-256: c31ccdec154d1fad7c73535fb7ab8050944ec0e2683f6b23b823a58caccbdf5b
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to potentially compromised websites or disposable hosting. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure and URL analysis strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://www.skk.com.hk/admin/ckfinder/userfiles/files/37441977942.pdf In PDF document text
    • http://louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/37726996891.pdfIn PDF document text
    • http://darec.sk/files/files/6362609619.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/nanvog2etqkh4ksb20jper1bct/38455465479.pdfIn PDF document text
    • http://rollfactorytogo.com/uploads/files/95786478326.pdfIn PDF document text
    • https://ppkh.net/userfiles/file/98445175377.pdfIn PDF document text
    • http://abwsalisbury.com/uploads/files/65223621367.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f1913dc2dbf---xutabarufo.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/1609540c9e27ff---91511758369.pdfIn PDF document text
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/rtmvkh11lbmb0dsur4hi54qf8b/73262834651.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/4f1157829ebffd868063c7bc1f052289/pumifewajuxus.pdfIn PDF document text
    • https://stalbeckers.nl/userfiles/image/file/10818976075.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/52441972878.pdfIn PDF document text
    • http://xn--90aoa5aj.xn--p1ai/ckfinder/userfiles/files/dovin.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/hn92p0d39boa3b4aaladlk4uu6/likojex.pdfIn PDF document text
    • http://moveworldtogether.com/datas/files/27380331272.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/c2ee65982f9458154e631b1a6ebbb064/83200369920.pdfIn PDF document text
    • https://gulertrafik.com/wp-content/plugins/super-forms/uploads/php/files/s4ch8h7ps86tjijgfe70h31e7i/sefirubafavejokisavulori.pdfIn PDF document text
    • http://malopolskiszlakwinny.pl/upload/File/xifejenibudisanojudet.pdfIn PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/budebavotadu.pdfIn PDF document text
    • https://accuratesearch.com/userfiles/file/bapojezurugumumub.pdfIn PDF document text
    • http://syuncyoku.jp/upload/file/30899864628.pdfIn PDF document text
    • http://sonnenheizungen.ch/fckeditor/editor/images/file/wukojufezapowejav.pdfIn PDF document text
    • http://assushop.com/userfiles/assushop.com/file/24214710320.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=imposters+handbook+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_off0000e9cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9CD 17652 bytes
SHA-256: 5ecfbc525f9a6cc4eecc3ac11a138148fd1547384b7eccd9710eb85e7b2043ee
font_01_sfnt_off000117d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117D2 10808 bytes
SHA-256: 95c83998b2e8f14f6f3d370c2e2833a9c2a5d71344b300b7b4cfe7e7443e326d
font_02_sfnt_off00013057.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13057 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1