Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4ebcc04541edb2d…

MALICIOUS

PDF

92.7 KB Created: 2021-09-15 19:24:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ddb8b86c159ccbfdea1373e58baa707f SHA-1: c4bbabf97cd552ff8378ea7cb16b957b736c693f SHA-256: f4ebcc04541edb2d4eabf94aa9412df932dd78f409d1508e073da4af582aa833
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which are structured to appear as document links, suggesting a phishing or credential harvesting attempt. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for a large number of links, further supporting a malicious intent. No scripts were extracted, but the presence of external URIs points to the document's primary function of redirecting users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 https://krisoc.ru/uplcv?utm_term=how+to+write+a+thesis+for+an+essay PDF link annotation
    • http://nato-denkmal.de/uploads/file/2026043158.pdfIn PDF document text
    • https://biocoop.legreniervert.fr/ckfinder/userfiles/files/tabuvapugo.pdfIn PDF document text
    • http://amoy-art.com/Upload/file/3323353246.pdfIn PDF document text
    • https://toliveinchristjesus.ceosale.catholic.edu.au/application/third_party/ckfinder/userfiles/files/ziwirurakulusunigamupova.pdfIn PDF document text
    • http://www.mab-solutions.fr/upload/file/93887081119.pdfIn PDF document text
    • https://www.agencesramos.com/ckfinder/userfiles/files/zatusuxabu.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/vimijuloxupakafoxafev.pdfIn PDF document text
    • https://fanaf.com/article_ressources/file/84357297558.pdfIn PDF document text
    • https://brothers-music.com/ckfinder/userfiles/files/27789464843.pdfIn PDF document text
    • http://locum-system.pl/userfiles/file/86930298581.pdfIn PDF document text
    • https://gymlesgeants.com/upload/editor/file/penawilamisunojoz.pdfIn PDF document text
    • https://terracell.info/images/file/97570238578.pdfIn PDF document text
    • http://votava2.altrodesign.eu/ckfinder/userfiles/files/44298305732.pdfIn PDF document text
    • http://bojovesporty.cz/userfiles/file/zivelowafakefane.pdfIn PDF document text
    • http://vpsystem.com/files/fck/nizotawozerekus.pdfIn PDF document text
    • http://verzorgingsindex.nl/images/uploads/19040718142.pdfIn PDF document text
    • http://ibookingkr.com/FileData/ckfinder/files/20210914_BBFC6C1B465E1589.pdfIn PDF document text
    • http://dayou.tw/uploadpic/files/202109041801552737.pdfIn PDF document text
    • http://alpinedelhi.com/userfiles/files/fagugawujid.pdfIn PDF document text
    • https://nstoplana.rs/ckfinder/userfiles/files/97053165083.pdfIn PDF document text
    • https://alev.az/userfiles/file/70961897108.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613238394bdbb---niriwosimikapafe.pdfIn PDF document text
    • http://kiapelhrimov.cz/UserFiles/File/jaruwupofofilexoniza.pdfIn PDF document text
    • http://consulcongress.it/uploads/assets/file/33809685756.pdfIn PDF document text
    • https://bvphcn.bdata.vn/upload/files/vanojomururam.pdfIn PDF document text
    • 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_off00010529.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10529 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011d3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D3B 18424 bytes
SHA-256: 77eed3a9a4b916ac2168e3389f3a743e31ab6f667af9ff671d21203eb39e63bb
font_02_sfnt_off00014cfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14CFC 10456 bytes
SHA-256: c0ca436bc67359a095872b79838da9abb6a65c148b615df3cb30680a48d1720c