Malicious PDF — malware analysis report

Static analysis result for SHA-256 52dffa44a85264cd…

MALICIOUS

PDF

82.6 KB Created: 2021-09-15 06:25:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c58c6e04b6d263f819d92b223b67e8fd SHA-1: 59f45382411c4b8b70cc9b44b5b0cacafac0fa1f SHA-256: 52dffa44a85264cd83427fde7b00bc181d459703b8de3b3cd49a1ae3092023bb
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to external resources and some are hosted on compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically identified as a phishing trojan. The document body is unreadable, but the heuristic firings suggest a link farm strategy, likely to lure users into downloading further malicious content or visiting phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://cardolf.ro/files/jogorexageneb.pdf In PDF document text
    • https://edu-mate.kr/_UploadFile/Images/file/38978798037.pdfIn PDF document text
    • http://medicom.pl/userfiles/file/laluzitovetamafoz.pdfIn PDF document text
    • http://hataylezzeti.com/resimler/files/jofagejoxuzuf.pdfIn PDF document text
    • https://tavfelugyelet.megujuloenergiapark.hu/admin/ckfinder/userfiles/files/89901619439.pdfIn PDF document text
    • http://cafehinglung.com/uploads/files/76755330551.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/161413e2541540---11342312602.pdfIn PDF document text
    • https://ldcpc.com/ckfinder/userfiles/files/dixeridivasize.pdfIn PDF document text
    • http://orvosvalaszto.hu/uploads/files/1164766077.pdfIn PDF document text
    • http://qualityspices.in/ckuploads/files/gasodipil.pdfIn PDF document text
    • http://studiopignotti.it/userfiles/files/borumikizivemowafivov.pdfIn PDF document text
    • https://poldercuptrofee.nl/site/admin/ckfinder/userfilesfiles/51856223800.pdfIn PDF document text
    • http://agrostroi-proekt.ru/ckfinder/userfiles/files/3826735701.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/ctafagpm2le476p3fderl66n9d/30557142978.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/b8e3nulcmjnoddphmso0drthi2/nawuderewasirimexawu.pdfIn PDF document text
    • http://miass.realxenon.ru/uploads/files/93446074213.pdfIn PDF document text
    • http://sake-tori.com/images/library/File/46395747661.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/161359a2b50461---73566437730.pdfIn PDF document text
    • http://corse.annuaire-regional.com/ckfinder/userfiles/files/48437755905.pdfIn PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/d42d190297ded867c97ce6bf3042f90b/8986315350.pdfIn PDF document text
    • https://preciseenergygroup.com/media/80271579578.pdfIn PDF document text
    • http://osmed.cz/app/webroot/files/files/momes.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=e2pdf+apk+download+for+pcPDF 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_off0000dd85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD85 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f59c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF59C 10404 bytes
SHA-256: 4db753237d866646dbf85bf830a83b12f435f2054deef8e9d0cc1e6fc933e694
font_02_sfnt_off00010d61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D61 18380 bytes
SHA-256: c70f8aca8c1735dd4ec1bfc482aa475d65279ffd65aee41739d43dc6b3dd1da0