Malicious PDF — malware analysis report

Static analysis result for SHA-256 07c166eac1be2311…

MALICIOUS

PDF

83.4 KB Created: 2021-09-14 06:51:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ffa786f65ba36e0ceead6fd14cd4dce6 SHA-1: 5f71e316cc8580de66b2d5a3a10f1fb9e95f8e7c SHA-256: 07c166eac1be2311637913aa980349186570cfe0bdd174a4f7988ed2c3c8c78b
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. It contains numerous external links, many pointing to PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior. While no scripts were explicitly extracted, the presence of embedded URLs and the overall structure strongly suggest a phishing or malware distribution attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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://nevisnews.com/userfiles/sudevak.pdf In PDF document text
    • https://dnmpaint.com/sdcc/images/file/4310212142.pdfIn PDF document text
    • http://sns.hu/_user/file/34104535336.pdfIn PDF document text
    • https://chambredhotes-savoie.com/ckfinder/userfiles/files/44536092432.pdfIn PDF document text
    • http://www.mueblesgamez.com/ckfinder/userfiles/files/tilotinuz.pdfIn PDF document text
    • http://veterinariomauracotti.it/userfiles/files/silazatesigij.pdfIn PDF document text
    • http://kfgame.snailgame.ru/upload/files/20210911013845.pdfIn PDF document text
    • http://studiolauramoschini.it/userfiles/files/15201025418.pdfIn PDF document text
    • https://mollis.rs/files/10948293433.pdfIn PDF document text
    • https://distriparkbotlek.nl/userfiles/files/pusegijovonurudeti.pdfIn PDF document text
    • http://www.singchai.co.th/ckfinder/userfiles/files/34134556073.pdfIn PDF document text
    • http://xn--b1amishc2fb.xn--p1ai/ckfinder/userfiles/files/wiretidedaruvopebitoso.pdfIn PDF document text
    • http://website-design-company.in/dev3/damodar/ckfinder/core/connector/php/userfiles/files/puzerawewid.pdfIn PDF document text
    • http://zekejozsef.eu/FCKfeltoltott/file/91829223496.pdfIn PDF document text
    • http://chia4kids.ru/ckfinder/userfiles/files/56363622888.pdfIn PDF document text
    • https://seger.cz/userfiles/file/bewinopojunifaguxirupinav.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138bc4a45f7b---66861620545.pdfIn PDF document text
    • https://dangeloremodeling.com/nbloom/fckuploads/file/xolonezotimode.pdfIn PDF document text
    • http://hebammenglueck.de/ckfinder/userfiles/files/82235288111.pdfIn PDF document text
    • http://koreaseowon.com/ckupload/files/97584436750.pdfIn PDF document text
    • https://sfeerweter.nl/userfiles/files/dawevexemikil.pdfIn PDF document text
    • https://ratosatu.com/contents/files/lavorajemumagajuto.pdfIn PDF document text
    • https://didaktika.drmix.cz/uploads/files/16977044983.pdfIn PDF document text
    • http://jujucuisine.com/userfiles/file/zemananabizasuwe.pdfIn PDF document text
    • http://tidomusica.com/uploads/files/202109132243161699.pdfIn PDF document text
    • http://kielcenoca.pl/files/file/gedimesowaxazediva.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=free+download+music+player+for+androidPDF 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_off0000de6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE6A 18644 bytes
SHA-256: 88d562e1f789e02c1531ecc960a080ed52c3b7a78a943285340e19f72bd890ff
font_01_sfnt_off00010e7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E7F 10960 bytes
SHA-256: d03ba9190646db67751448fd9093804b2f288f608fe31ba1df74ad7c61725132
font_02_sfnt_off000127ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1