Malicious PDF — malware analysis report

Static analysis result for SHA-256 85d1f51894ff5ac9…

MALICIOUS

PDF

84.9 KB Created: 2021-09-09 03:43:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 3163e59c31de1118791a6c9d0b2ef70a SHA-1: 9f27731a27dddaffb10b914f3bbbaf0d8d740aa3 SHA-256: 85d1f51894ff5ac9e60676ea85b60415d77a6e007d151fed1bb67d82a99efdb9
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URIs and is identified as a link farm on disposable hosting, suggesting it's designed to redirect users to potentially harmful sites. The presence of embedded URLs and the PDF structure itself point towards a phishing or malware distribution lure, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://pistant.ru/uplcv?utm_term=react+native+run+android+specific+device PDF link annotation
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/36906a3b7b214f6a5ee30b673d69d718/kugudew.pdfIn PDF document text
    • https://efficimm.fr/userfiles/files/72304205540.pdfIn PDF document text
    • http://kondicionery-himki.ru/upload_picture/file/ditofifaxidowebig.pdfIn PDF document text
    • https://guptajimarriagebureau.com/userfiles/file/30448267276.pdfIn PDF document text
    • http://hanaelectric.com/userData/board/file/48917760922.pdfIn PDF document text
    • http://ziva-muzika.cz/files/file/58202483912.pdfIn PDF document text
    • http://zvezda-rostov.ru/ckfinder/userfiles/files/96327977085.pdfIn PDF document text
    • http://tobn56.com/UpFiles/file/77502915164.pdfIn PDF document text
    • http://silarperu.com/UserFiles/file/34963186989.pdfIn PDF document text
    • https://kop-trans.pl/uploads/userfiles/files/kibuvixoda.pdfIn PDF document text
    • http://kermiradiatoriai.lt/images/files/tuzejog.pdfIn PDF document text
    • https://drisraadentalcenter.com/userfiles/file/xonodewo.pdfIn PDF document text
    • https://ijacr.net/assets_admin/ckfinder/core/connector/php/uploads/files/50410356424.pdfIn PDF document text
    • http://czernavendeghaz.hu/admin1/file/kasiku.pdfIn PDF document text
    • http://prunay-en-yvelines.fr/ckfinder/userfiles/files/61541827326.pdfIn PDF document text
    • http://studiotecnicoligioni.com/userfiles/files/nawarepol.pdfIn PDF document text
    • https://almentispharma.com/ckfinder/userfiles/files/fikisu.pdfIn PDF document text
    • https://dpengineers.info/admin/userfiles/file/85667332718.pdfIn PDF document text
    • http://vietsonplastic.com/uploads/userfiles/file/27270434651.pdfIn PDF document text
    • http://art-wonders.com/ckeditor/ckfinder/core/connector/php/uploads/files/dulukipavuvuzewar.pdfIn PDF document text
    • http://freestyler.cz/img/file/namagasixusurarad.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139392e0d66f---64171168231.pdfIn PDF document text
    • https://atcotourismtravel.com/userfiles/file/wulasulaf.pdfIn PDF document text
    • http://drprdesaihospital.com/uploads/tegixopabiwuvupakove.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_off0000e331.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE331 18732 bytes
SHA-256: b922defd8b44859abd469c6eee7cf946ed1b9f3d9925f1bdbf1500830892b173
font_01_sfnt_off0001139a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1139A 10776 bytes
SHA-256: 7bdc72a26f045b2577f3e5b2310d145fc6077e843795a2bec916783745f02ab0
font_02_sfnt_off00012c97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C97 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1