Malicious PDF — malware analysis report

Static analysis result for SHA-256 551717653c4a1071…

MALICIOUS

PDF

73.3 KB Created: 2021-09-12 00:20:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 283181579f5c6cebf52f59aeefb93278 SHA-1: b997ff30c92385b21fe12597ce1cf5db7ab9cb4c SHA-256: 551717653c4a10711825ab7c99f41b36a3fc2d1567a8d5f3daa53e5240b505ce
166 Risk Score

Malware Insights

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

The sample is a PDF document flagged by ML classifiers and ClamAV as malicious, exhibiting characteristics of a phishing and trojan delivery mechanism. The heuristic 'SE_BROWSER_INSTALL_LURE' indicates the document attempts social engineering to trick users into installing malicious browser extensions or updates. While no scripts were directly extracted, the PDF structure and embedded URLs suggest it may exploit vulnerabilities or redirect to malicious sites to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://stadtbild-intervention.de/Quansis/ckfinder/userfiles/files/womunamunesajiradi.pdf In PDF document text
    • http://sindikat777.ru/ckeditor/ckfinder/core/connector/php/uploads/files/38543376698.pdfIn PDF document text
    • http://burbank.kopanramen.com/uploads/files/11128727660.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/161398d1118f6d---90686056034.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132b40a71334---1236973138.pdfIn PDF document text
    • https://trompis-tondschungel.de/userfiles/file/dusizibejipuvirazada.pdfIn PDF document text
    • https://matfplayer.com/calisma2/files/uploads/34678043109.pdfIn PDF document text
    • https://demo-calson.garment-pro.com/ckfinder/userfiles/files/jafen.pdfIn PDF document text
    • http://shyjjc.com/v15/Upload/file/20219418568673.pdfIn PDF document text
    • http://haisushitogo.com/uploads/files/rifefakimotoxogepobew.pdfIn PDF document text
    • https://watertorens.nl/userfiles/file/gagejepufubigaxajoluze.pdfIn PDF document text
    • http://www.psoevalledeabdalajis.es/ckfinder/userfiles/files/fobenudakimupan.pdfIn PDF document text
    • https://isigakizima.net/img/tmp/file/bopamimekatapavijasil.pdfIn PDF document text
    • http://alituncer.com/userfiles/file/9894811372.pdfIn PDF document text
    • http://pietroquatriniarchitetto.eu/userfiles/files/4277741288.pdfIn PDF document text
    • http://zhizhencn.com/filespath/files/20210902110930.pdfIn PDF document text
    • https://hijaulumut.com/contents/files/zuser.pdfIn PDF document text
    • http://henghuitong.com/jingkelun/userfiles/files/20210906083524.pdfIn PDF document text
    • http://goldnumber.info/userfiles/file/23520542068.pdfIn PDF document text
    • http://travelsi.ru/ckfinder/userfiles/files/vejutafeguwovufe.pdfIn PDF document text
    • http://chandravanshi.com/userfiles/file/77920556316.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=universal+bypass+google+chrome+extensionPDF 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_off0000bb95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB95 16456 bytes
SHA-256: 4bba307063e34c366f469a2ea3bdf7cb2f27d5da708444b7ebe101e26199453f
font_01_sfnt_off0000e60e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE60E 11248 bytes
SHA-256: 1434af75473240372ec2e3f3cadc065043616c3c9ff4501442035ec5daca07a2
font_02_sfnt_off00010020.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10020 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1