Malicious PDF — malware analysis report

Static analysis result for SHA-256 fd9e4ff8440338da…

MALICIOUS

PDF

69.7 KB Created: 2021-10-03 00:50:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: fc7ae103737b1447b66fde7b21c46a7e SHA-1: f1ed52fcde77360df6bfa417516c572c329194b6 SHA-256: fd9e4ff8440338da0c48fa030aa6e3e8c0b7a645a58a52052a56f4af4597f6d8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm on disposable hosting, with numerous embedded URLs pointing to PDF files. The document body is heavily obfuscated and unreadable, suggesting it is designed to conceal its true purpose. The primary attack pattern involves directing users to a network of potentially malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://caythuocdangian.net/images/files/94450544343.pdf In PDF document text
    • http://kaies.net/upfiles/file/javaxanumosofeg.pdfIn PDF document text
    • http://stomerijindex.nl/images/uploads/58999294529.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1613bec821e18a---lapajuza.pdfIn PDF document text
    • http://elitacasa.it/images/file/vebiguwovopuzi.pdfIn PDF document text
    • http://smm-mm.com/uploads/news_file/20255954677.pdfIn PDF document text
    • https://kermoulin.com/userfiles/file/selodifewoso.pdfIn PDF document text
    • http://okna-kurska.ru/page_edit/_samples/userfiles/files/88353123770.pdfIn PDF document text
    • https://csam-villepinte.org/uploads/images/file/4974265251.pdfIn PDF document text
    • http://tpdw.pl/userfiles/file/25466974111.pdfIn PDF document text
    • http://ghibms.com/userfiles/files/jujekujodopulim.pdfIn PDF document text
    • http://wib24-admin.de/uploads/file/sevozobaborukifesefane.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/zovakatawurenutimi.pdfIn PDF document text
    • http://ventilatoryzlin.cz/images/file/77002508931.pdfIn PDF document text
    • http://scandirent-new.ru/uploads/assets/file/25385611740.pdfIn PDF document text
    • https://suavitinhtannha.net/upload/files/36574120087.pdfIn PDF document text
    • https://estoniapools.com/contents/files/95806247482.pdfIn PDF document text
    • https://rsvforum.com/userfiles/file/96117369760.pdfIn PDF document text
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/993bd1f25e89b7737e154e73b7441945/dolopik.pdfIn PDF document text
    • http://captaincook.hu/userfiles/file/62094021950.pdfIn PDF document text
    • http://xn--4k0b43gkwo4gn.com/upload/editor/file/71398141884.pdfIn PDF document text
    • http://haliburtonhighlandsheritage.ca/userfiles/file/ruvegimivitidi.pdfIn PDF document text
    • http://offerseir.com/basefile/offerseircom/files/57649907921.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=composition+meaning+in+chemistryPDF 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_off0000ae34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE34 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c646.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC646 16324 bytes
SHA-256: af8a05eb45f993c5f71efa52d8b2711f7ae25210445cd6af9e8db45490cd417e
font_02_sfnt_off0000eff5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFF5 10920 bytes
SHA-256: bfa891a554b5b201c3a0aa8661867ca13e9a98595920bef1046312c9bfcce030