Malicious PDF — malware analysis report

Static analysis result for SHA-256 f52e35b3c78d62df…

MALICIOUS

PDF

72.0 KB Created: 2021-09-18 16:32:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b35e95c40b558cfb14fc992e9d99a39b SHA-1: 43c293bac19a437b738357ac15e76e01701f1fd6 SHA-256: f52e35b3c78d62dfeb2c85ca8478b5caf458156063344b4460e87e0262c8231b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to disposable hosting, suggesting a link farm designed to redirect users to malicious content. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically flags this behavior, and the presence of external URIs further supports this. While no scripts were explicitly extracted, the nature of the PDF and its embedded links strongly suggests it's used for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://allytemp.ru/uplcv?utm_term=tubemate+1080p+video+downloader+apk PDF link annotation
    • http://boilerservis.ru/uploads/files/togemitupikaxaxoto.pdfIn PDF document text
    • http://rana-international.com/userfiles/files/tijafuretagideze.pdfIn PDF document text
    • http://bapassamarinda.id/assets/ckfinder/core/connector/php/uploads/files/31971910230.pdfIn PDF document text
    • http://dentish.ru/ckfinder/userfiles/files/58223638895.pdfIn PDF document text
    • http://bedrucken24.de/userfiles/file/13857951235.pdfIn PDF document text
    • https://mepho.hu/ckfinder/userfiles/files/74569701934.pdfIn PDF document text
    • https://shindah.com/images/ckeditor_img/files/82970748952.pdfIn PDF document text
    • http://gerocuki.hu/user/file/gobupeguxobetojefuzo.pdfIn PDF document text
    • https://futurefacesnyc.com/uploads/file/42519705691.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/161376141995bf---30200408170.pdfIn PDF document text
    • http://quangcaovuanh.com/vietkiendo/upload/file/pejopiziragigavun.pdfIn PDF document text
    • http://vetusmeter.com/images/upload/File/dapeweg.pdfIn PDF document text
    • https://digireg.org/upload/93384033186.pdfIn PDF document text
    • https://ijpdua.com/contents/files/62694762613.pdfIn PDF document text
    • http://koreaseals.com/ckfinder/userfiles/files/13357714190.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/97434577348.pdfIn PDF document text
    • http://digitalpolicycouncil.org/imagenes/file/42067902971.pdfIn PDF document text
    • http://studiotecnicoligioni.com/userfiles/files/76535084227.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614200c11247f---zipejamanogarerexafa.pdfIn PDF document text
    • https://ntct-dz.com/ckfinder/userfiles/files/somuliriwelamirujeses.pdfIn PDF document text
    • https://e-casainteligenta.ro/userfiles/file/46316544550.pdfIn PDF document text
    • https://advik.net/userfiles/file/33524080790.pdfIn PDF document text
    • http://seychelles-resort.com/images/blog/file/39689741579.pdfIn PDF document text
    • https://fallsplat.se/bildbank/file/gevumawap.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_off0000b5e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5E2 16732 bytes
SHA-256: a2edbfc3724e647263a4f0b90912e125ddfde03adebe6d36defc0d272d868c27
font_01_sfnt_off0000e06e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE06E 11216 bytes
SHA-256: 107b713cbae54f96f15485c1ff86ddbbb00f71b7d205ff1a220615bd25fbec72
font_02_sfnt_off0000fa89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA89 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1