Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b3dda69d67d3085…

MALICIOUS

PDF

86.0 KB Created: 2021-09-07 18:37:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 8f9d004403a97c35242b89f319eafe02 SHA-1: b4d6d863ac7f379c3e9757e53e7223906ffdfbde SHA-256: 4b3dda69d67d3085369eaa091080d34af72867be456c3836959b7c7cfb1723cd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV and an ML classifier as malicious, specifically as a phishing trojan. It contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF-specific heuristics like 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' reinforces the malicious intent of redirecting users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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://vakaruinzinerija.lt/userfiles/file/pojopaxukifiburono.pdf In PDF document text
    • http://gleneaglehoa.org/images/file/60585345682.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16090344891d0c---vigipekexajesinajedodegu.pdfIn PDF document text
    • https://vrindaindia.com/php/joseph/uploads/file/94202418738.pdfIn PDF document text
    • http://dancephoto.ru/userfiles/files/wovakimad.pdfIn PDF document text
    • https://nutricount.cz/UserFiles/File/josamasebexetanukelabo.pdfIn PDF document text
    • https://mangonebike.com/uploads/file/25063856362.pdfIn PDF document text
    • http://webinside.pl/userfiles/file/xebaxo.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/160878ef9c7b97---wodewut.pdfIn PDF document text
    • http://perfectthesale.com/wp-content/plugins/formcraft/file-upload/server/content/files/160809d9b7eb4f---65440691705.pdfIn PDF document text
    • http://pdww.ru/ckfinder/userfiles/files/42147362166.pdfIn PDF document text
    • http://tekizolasyon.com/ckfinder/userfiles/files/5518452557.pdfIn PDF document text
    • http://xn--b1ahhafccpgkb2bxo.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0920b26650d2e00e3aea2783e50aff04/48685069381.pdfIn PDF document text
    • http://gramercy-grand.ru/files/file/muvurajebokoliwofex.pdfIn PDF document text
    • https://ajitcoatings.com/uploads/85221623123.pdfIn PDF document text
    • http://nessium.net/userfiles/file/13873328546.pdfIn PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af10598cdf5---bemusiwikapena.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3a0a03706---kemerasemol.pdfIn PDF document text
    • http://h-st.nl/bestanden/files/sewogikovivofonikir.pdfIn PDF document text
    • https://bakotech.at/uploads/ckeditor/files/nisajetupame.pdfIn PDF document text
    • http://phongthuyphatloc.com/luutru/files/punarugakitop.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/f0691f8c3f5b6fb0984c6c019dba6af2/bumadexuludozore.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/30f4d31b32eb6dd22d885b284450645e/65121833260.pdfIn PDF document text
    • http://olympusflights.com/files/files/ruleparesevu.pdfIn PDF document text
    • http://busanpc1.com/upload/fckeditor/file/18067493449.pdfIn PDF document text
    • http://btc-ltd.com/upload/file/nuxogiriwo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=sarna+sarcoptica+canina+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_off0000ed84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED84 10512 bytes
SHA-256: 0cc40f8479ae64841593db86c77a64ea52fe547c7b94673d5765f18b8128a487
font_01_sfnt_off00010580.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10580 17356 bytes
SHA-256: a2112ab8abf103439aa7fda092c68c4457a33ac03b00cd06d96d1895047f48ac
font_02_sfnt_off0001322e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1322E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1