Malicious PDF — malware analysis report

Static analysis result for SHA-256 671a261853cf96f5…

MALICIOUS

PDF

117.1 KB Created: 2021-09-03 23:00:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 4cdbd6d9f329b8868ab78fd3480de3bc SHA-1: cfbc352e69cff9c8f6150936816abd9f0307e141 SHA-256: 671a261853cf96f54f2b929002e07f06b763e2fbf653cb1e684663055e20edf0
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, pointing to numerous external URLs, some hosted on compromised CMS uploads. The document body is heavily obfuscated, preventing analysis of its direct content, but the overall structure and heuristic firings strongly suggest a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://artgraf24.pl/userfiles/file/17012415283.pdf In PDF document text
    • http://voyagevietnamlaos.com/hinhanh/file/lakexorejuzamiwedonuweki.pdfIn PDF document text
    • http://derma-dts.de/files/file/jajojegawa.pdfIn PDF document text
    • http://modernplating.com/userfiles/file/seban.pdfIn PDF document text
    • https://www.sehersirin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077bae200023---15214206633.pdfIn PDF document text
    • https://speakingparrot.com/upload/ckfinder/files/gorutelilezinunavunokog.pdfIn PDF document text
    • http://www.cerathai.com/image/upload/File/piviwagazoxoz.pdfIn PDF document text
    • http://jhdjt.com/images/upload/File/xoretopuralaluxedamipited.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/bb5b11e0d4d3a0da3a42d7724984eae3/rawirebadomozipub.pdfIn PDF document text
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/e4894h84i1k8qkgfhkpe2dm2nm/81623604251.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/4n8im8mjhnet97k6o77tffmoe1/pezipogiketenot.pdfIn PDF document text
    • http://sahamit.net/userfiles/file/36677180838.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/da947ff02b096e93e4be8344eb2ba1b0/59870950320.pdfIn PDF document text
    • https://cowichanseniors.ca/userfiles/file/vabifafejifamibatesol.pdfIn PDF document text
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/160834d9042805---3173703849.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607305b982d5c---89906652336.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16099a1c453c67---14958506733.pdfIn PDF document text
    • http://pampa.be/uploads/userfiles/files/53519952901.pdfIn PDF document text
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/9254322d2780dc90f7f31f7b88b833f6/4234764096.pdfIn PDF document text
    • http://ozari-ua.com/files/file/50955742156.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/vrvll1vf7kbhc6kbqirjjt341t/8689745622.pdfIn PDF document text
    • http://3e-recycling.ru/app/webroot/filesfiles/42124400077.pdfIn PDF document text
    • http://sadiqandsons.com/userfiles/files/62983935619.pdfIn PDF document text
    • http://www.cenlafilm.com/siteuploads/editorimg/file/bukixokererilenozeravum.pdfIn PDF document text
    • http://coreaad.com/DreamDataUpload/file/wujujajij.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=here+comes+the+sun+solo+guitar+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_off000162ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x162ED 18880 bytes
SHA-256: 604838fd7a8ca485756fcd4b265702bb7e85c01b0fb2ff49eaa3e86cccfa56ca
font_01_sfnt_off00019490.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19490 11160 bytes
SHA-256: cc96690b2b561507d9e8dfc5f6ffbafc6044c9bdc212b54dac8fa9fc60c26976
font_02_sfnt_off0001ae34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1AE34 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1