Malicious PDF — malware analysis report

Static analysis result for SHA-256 6f671531a9f4a98b…

MALICIOUS

PDF

73.1 KB Created: 2021-09-09 00:50:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 81f5ddf583e0dffaa0029740a3cf31d7 SHA-1: 0681a08f4d97398b3b5202b3dcfa1bfd2080e561 SHA-256: 6f671531a9f4a98badbf27c00f986e6c3ce93415df7110c27a4a4531e6a71c03
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress upload directories, suggesting a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the URL structure and heuristic firings are sufficient for this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137e06916fa5---27460520404.pdf In PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/161345081d71ed---dijoma.pdfIn PDF document text
    • https://everestart.com/images/stories/file/xuvibarisusefepiper.pdfIn PDF document text
    • http://demo755.webbazaar.com/uploads/52443562329.pdfIn PDF document text
    • http://designklasse.de/ckfinder/userfiles/files/96614821979.pdfIn PDF document text
    • https://nabijdefossa.nl/upload/files/jozagaruro.pdfIn PDF document text
    • http://avesta-hmora.boj.se/uploads/userfiles/files/kijamolazogu.pdfIn PDF document text
    • http://laihoawedding.com/app/webroot/upload/files/sanut.pdfIn PDF document text
    • http://asijskepotraviny.cz/files/file/58070923894.pdfIn PDF document text
    • https://shieldtech.cz/ckfinder/userfiles/files/taleferututapixom.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/161316c658e5b7---77817297393.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137c292b5ec1---wotoligolurawozomos.pdfIn PDF document text
    • http://aristosaigonhotel.com/uploads/files/6125856468.pdfIn PDF document text
    • http://japan-railpass.info/images/blog/file/80355847369.pdfIn PDF document text
    • https://ruta.hu/ckfinder/userfiles/files/vojunamusufu.pdfIn PDF document text
    • http://anneadamslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/puzuwukefomebesigogesewi.pdfIn PDF document text
    • http://orem.mn/uploads/files/70757838101.pdfIn PDF document text
    • https://sunsoftinfoway.net/ckfinder/userfiles/files/doxafidotubapatadad.pdfIn PDF document text
    • http://anpharma.net/upload/files/masetej.pdfIn PDF document text
    • https://euroquimicadistribucion.com/zabaleta/data/imagenes_contenidos/file/kebep.pdfIn PDF document text
    • http://makrostal.pl/user_images/file/19830163635.pdfIn PDF document text
    • http://corkpotters.com/images/99558205491.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=dice+throne+adventures+rulebook+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_off0000bc03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC03 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d415.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD415 16172 bytes
SHA-256: 29fb0c11a738e28eeb73191c44c3b7e949a0ce7c693904bce50167fad3bd7f0e
font_02_sfnt_off0000fd36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD36 11116 bytes
SHA-256: c7aa404dbb374373484f117ad9c546b098ed4444123306052a236ed9d24985f6