Malicious PDF — malware analysis report

Static analysis result for SHA-256 29ecd59a80bab77a…

MALICIOUS

PDF

72.9 KB Created: 2021-10-10 18:15:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 4bb1476585ee3fdbe9a9cc433b79b939 SHA-1: f903bf30df329531c6bfca3d7d7ef22d3db053ab SHA-256: 29ecd59a80bab77ab4c53d75eb48698d6503ce9cc394fbe79b0dcef4f5a94f10
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, specifically identified as a phishing trojan. It contains numerous embedded URLs that point to various domains, many of which are associated with link farms and compromised CMS uploads. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://synerhu.ru/uplcv?utm_term=heart+failure+signs+and+symptoms+pdf PDF link annotation
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/wirugopemixugususavot.pdfIn PDF document text
    • http://orsini-blasioli.it/userfiles/files/82879587986.pdfIn PDF document text
    • https://datenglagi.com/contents/files/gilavazajare.pdfIn PDF document text
    • https://5of7edwardstreet.com/assets/media/files/witipubavisanuvoxa.pdfIn PDF document text
    • http://xyr59.com/filespath/files/20210929131646.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210905055803.pdfIn PDF document text
    • http://alde-pace.org/ckfinder/userfiles/files/6143642259.pdfIn PDF document text
    • http://tvsatkrosno.pl/userfiles/file/86318689323.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d287904d5e---55652318676.pdfIn PDF document text
    • http://gekon.net/userfiles/file/83074634945.pdfIn PDF document text
    • http://519pf.com/userfiles/files/gopidutovetonulebewew.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/161527e61b9694---kowinijawaburekud.pdfIn PDF document text
    • https://dodomacnosti.net/data/file/24800718671.pdfIn PDF document text
    • https://www.ccs-corporation.com/ckfinder/userfiles/files/gawiwusuzidodigo.pdfIn PDF document text
    • http://mixline.ru/img/lib/file/bugedetugikunog.pdfIn PDF document text
    • https://rts-wm.com/ckfinder/userfiles/files/84830453976.pdfIn PDF document text
    • http://abwrva.com/uploads/files/71717636043.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/l2sp2dpl6edkbfu5kq2eirlqrq/gavujidezemevasigunofobe.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/16132658803828---99212199385.pdfIn PDF document text
    • http://vietnam-intraco.com/webroot/img/files/dotefaterejif.pdfIn PDF document text
    • http://vrtaspol.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/kidugatupokagubakebor.pdfIn PDF document text
    • http://pnmanagementsolutions.in/uploads/ziroxage.pdfIn PDF document text
    • 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_off0000b832.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB832 17188 bytes
SHA-256: a2efc578ad402aa9221fe3c8383a71c1e8ae93468af54a0fb62936b8206689d6
font_01_sfnt_off0000e437.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE437 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fc4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC4E 11044 bytes
SHA-256: e70a1f7fe412cc0c54a70889def034926abc024fcf0f4a68c2a121e10de0cf34