Malicious PDF — malware analysis report

Static analysis result for SHA-256 18fd7ac457b4ee5d…

MALICIOUS

PDF

74.0 KB Created: 2021-09-18 22:10:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 9908e95a79d73ad8d590cda92543decb SHA-1: 6492837a6c1313a0ae5b4c56fd7b1e7428737995 SHA-256: 18fd7ac457b4ee5db3389ed75ec6d2048577a957fceaac8f9025169ed2de0bfc
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to suspicious PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates these links are likely used to obscure the true destination or distribute malware. No scripts were extracted, but the presence of external URIs and the overall detection suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://patrick-vallot.com/upload/files/nusafom.pdf In PDF document text
    • http://bargiel.com.pl/ckfinder/userfiles/files/21021796686.pdfIn PDF document text
    • https://taechoclub.com/FileData/ckfinder/files/20210906_0D63F5BBD76B8DE8.pdfIn PDF document text
    • https://armagedonspedycja.pl/files/file/48457733948.pdfIn PDF document text
    • http://pkynfe.net/userfiles/file/64431915167.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/16141f97defcf1---86843862019.pdfIn PDF document text
    • https://lazerom.pro/media/file/mufaxudatidejojug.pdfIn PDF document text
    • https://curtain.jinware.com/upload/files/lipunulonunujomuwojuwegu.pdfIn PDF document text
    • https://bimstudioinc.com/media/files/vudububetubololuwaroxoro.pdfIn PDF document text
    • https://e-casainteligenta.ro/userfiles/file/dugunezuwum.pdfIn PDF document text
    • http://suachuaspa.com/upload/images-content/files/42376817991.pdfIn PDF document text
    • http://avvocato-callegaro.it/public/file/jeranuziturepovikunex.pdfIn PDF document text
    • http://patp1ryb.ru/media/file/takozitunubojubaxir.pdfIn PDF document text
    • https://adamslakeband.org/userfiles/file/10202730543.pdfIn PDF document text
    • https://systematix.pl/userfiles/file/fugokosa.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/d89357d7933e2b21204a198432765c95/69843852194.pdfIn PDF document text
    • http://tsraccountants.nl/mailing/images/photo/file/70541233362.pdfIn PDF document text
    • http://rymwid-training.com/userfiles/file/408125166.pdfIn PDF document text
    • http://www.ags-sib.ru/ckfinder/userfiles/files/sefunelajef.pdfIn PDF document text
    • https://intersat.lv/files/file/67113637875.pdfIn PDF document text
    • http://thuocnam.xyz/images/files/donuwodulonalonadasunomor.pdfIn PDF document text
    • http://www.instalacionescueto.com/nueva/ckfinder/userfiles/files/zepiwokoxur.pdfIn PDF document text
    • https://hospvetcentral.pt/site/upload/file/belugofofenokodadopoketuj.pdfIn PDF document text
    • http://smirna.pl/files/file/pojodijuwexifi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=20000+leagues+under+the+sea+book+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_off0000ba72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA72 17792 bytes
SHA-256: 81b06fa178144c90aa426819af33f7019d83374304d6198a3247806159730a96
font_01_sfnt_off0000e898.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE898 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000100af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100AF 11164 bytes
SHA-256: c1f5ab18244a1d0e6ac4bbea64c89ddf3f7f5bd5e26b207f44e6c2f69d54b1f9