Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3b21394b9cd1deb…

MALICIOUS

PDF

74.1 KB Created: 2021-09-21 12:49:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 3b3cd53b75e9655ccc757f8f54bd7a96 SHA-1: d8a2de1ed3cf789d410ee4881af0752a22ed86d6 SHA-256: c3b21394b9cd1debe6b24ec47346d8985211115e2c3a498101607e0d2d593c91
156 Risk Score

Malware Insights

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

The PDF file contains a link farm directing users to multiple external URLs, several of which are hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9827

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://www.wm-meyer.de/meyer/admin/editor/ckfinder/userfiles/files/fupewabuxekikibewovumomu.pdf In PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/3676682e32c22a88aed9ef236ace13ca/lipoxis.pdfIn PDF document text
    • https://wineart.online/userfiles/file/nemigawebowurozubejod.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/u988qln8j1qju9ba0nadi7kk5o/vituxupusogukipobos.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/b54b49ede534def7a2161845db2af8eb/munegaraluzipupumaxadabe.pdfIn PDF document text
    • https://pisangmanis.com/contents/files/61370986986.pdfIn PDF document text
    • https://www.soroptimist.be/oldsite/intranet/ckeditor/ckfinder/userfiles/images/files/92648019521.pdfIn PDF document text
    • http://ychnjl.net/userfiles/files/vibukekaguxe.pdfIn PDF document text
    • https://akgoz.zemta.com/uploads/files/58918420005.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/d6452520a3bf0489223c18d6ee0f33d0/melitodomixinakozo.pdfIn PDF document text
    • http://magiepourenfants.com/images/mediamanager/file/48726768274.pdfIn PDF document text
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/afed3395f2bc937e421d190014d11403/58463570267.pdfIn PDF document text
    • http://allineers.morefriendship.com/upload/files/sisuzemadobex.pdfIn PDF document text
    • https://study-abroad-travel.com/ckfinder/userfiles/file/pidoxisomifule.pdfIn PDF document text
    • http://uceng.net/_UploadFile/Images/file/delopasegisusologek.pdfIn PDF document text
    • http://kovacsoltvaskerites.hu/images/file/64317861294.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/f57c89919c43cc5db10e1b6320435172/13489322463.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/161408d2fe551c---tulamamipuw.pdfIn PDF document text
    • https://postele-z-masivu.sk/ckfinder/userfiles/files/fiforuvolaxikanuz.pdfIn PDF document text
    • https://felicityokolo.com/file/45513506660.pdfIn PDF document text
    • http://hflbdq.com/uploads/file/041332068084.pdfIn PDF document text
    • http://vibrobreaker.com/files/files/80119052708.pdfIn PDF document text
    • https://4cmedica.com/ficheiros_upload/file/95651648478.pdfIn PDF document text
    • http://woodwork.pl/ubezpiecz/obrazy/file/wukixibo.pdfIn PDF document text
    • http://www.museopizarra.com/ckfinder/userfiles/files/belubiso.pdfIn PDF document text
    • https://lmbri.com/WYSIWYGImage/file/46170797363.pdfIn PDF document text
    • http://needychild.org/ckfinder/userfiles/files/57426287813.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=apk+not+installing+androidPDF 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_off0000c152.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC152 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d969.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD969 10508 bytes
SHA-256: d81a427f1f0a41aa5633ab03834e481f86ec92d04763f87c45b3c2bb0b207cc6
font_02_sfnt_off0000f140.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF140 16264 bytes
SHA-256: 261fd917bb45953e9a3ce05f0e7e51733dad88b4bb72a245543c6edf2c5e9817