Malicious PDF — malware analysis report

Static analysis result for SHA-256 a99c757ecb990d27…

MALICIOUS

PDF

84.1 KB Created: 2021-09-13 12:46:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: e6eed06fc3710971da109b1732610244 SHA-1: e33f07b39042a764e5e7fc29572faea1d5b3b8ed SHA-256: a99c757ecb990d276c327c2d52af5588cd88652c7d1d1e7072d8d4a45f377af6
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it is a link farm designed to lure users into installing browser extensions or updates. While no scripts were directly extracted, the nature of the heuristics and the embedded URLs suggest a phishing or malware distribution attempt, likely leveraging a browser exploit or social engineering to achieve its goals.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://laser-piskovani.cz/democms/userfiles/file/48528707436.pdf In PDF document text
    • https://renetravel.ro/images/files/kuworodubovibekopuruzi.pdfIn PDF document text
    • https://linkevicius.com/upload/galery/file/81225011265.pdfIn PDF document text
    • http://fzcce.com/aimgs/uload/files/gavisibobijesaxupojagovod.pdfIn PDF document text
    • https://haisanquangninh.org/data/dulieu/files/zejedipe.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/54830297138.pdfIn PDF document text
    • http://gardenofsound.com/userfiles/files/12612005011.pdfIn PDF document text
    • http://zetrade.cz/userfiles/file/goxapotigilu.pdfIn PDF document text
    • http://reanda.com/jingkelun/userfiles/files/20210904153139.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161308ae955ac3---77892572083.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613dca34d3ca2---dalegipegilim.pdfIn PDF document text
    • http://ski-experience-japan.com/images/blog/file/25198309380.pdfIn PDF document text
    • http://fence-alarm.com/userfiles/files/waguselu.pdfIn PDF document text
    • http://motorlustor.net/userfiles/file/lokamoputopugunug.pdfIn PDF document text
    • http://baobianhkhang.com/upload/files/penuse.pdfIn PDF document text
    • https://resortweeks.pro/userfiles/file/sugadipuzulas.pdfIn PDF document text
    • https://upbfassadenbau.com/upload/file/nodinupobes.pdfIn PDF document text
    • http://bsbcarpet.com/userfiles/file/99197156110.pdfIn PDF document text
    • https://interativacorretora.com/fotosempresa/files/41135807498.pdfIn PDF document text
    • http://www.lovebliss.tw/UserFiles/files/xinovatasirilaxevowexu.pdfIn PDF document text
    • https://abss.pt/userfiles/file/50033846829.pdfIn PDF document text
    • https://beaszemin.com/files/25160643717.pdfIn PDF document text
    • http://maasmartcity.com/userfiles/file/9824781531.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=how+to+install+chrome+in+android+tvPDF 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_off0000df20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF20 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f737.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF737 10780 bytes
SHA-256: 8cc312df633f41658b097d2b07e0da223ff583472938dbad2863df860f05e914
font_02_sfnt_off00010fdc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FDC 19656 bytes
SHA-256: e12cf4c06aaf7b4c47b4fa59db0ab54b2ee46dcac54ec3dae013787e32b70527