Malicious PDF — malware analysis report

Static analysis result for SHA-256 940e31aec5683a98…

MALICIOUS

PDF

70.7 KB Created: 2021-09-25 01:38:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d3ad9f639d4956ca071fbcc76af1bc04 SHA-1: 6eed6f26520382da4a8b2618ebf7ea6d38e7fc36 SHA-256: 940e31aec5683a98c1b48ae6f524615e2fe8b9af25f3d222f2a43f7770a9168f
126 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. The presence of numerous embedded URLs pointing to various domains, many of which are structured as link farms, suggests an attempt to manipulate search engine results or distribute additional malicious content. The document body is unreadable, but the heuristics and URL analysis strongly point towards a phishing or SEO-based attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://jazykovytabor.topenglish.sk/app/webroot/gallery/files/15113981847.pdf In PDF document text
    • https://mannerfeltdesignteam.se/ckfinder/userfiles/files/revafuletujozatituteberi.pdfIn PDF document text
    • http://attlas.center/userfiles/file/vetikuxelowuba.pdfIn PDF document text
    • http://brette-animation.com/userfiles/file/masojar.pdfIn PDF document text
    • http://ymmicro.com/files/files/657403442.pdfIn PDF document text
    • http://graczeonline.pl/userfiles/file/muzusuvi.pdfIn PDF document text
    • http://liily.jp/upload/file/20210907143703.pdfIn PDF document text
    • http://vallovin.it/userfiles/files/85921769318.pdfIn PDF document text
    • http://kriosispl.com/cote_dor_import/admin/ckfinder/userfiles/files/11535325297.pdfIn PDF document text
    • https://coffotea.com/uploads/files/202109241522011985.pdfIn PDF document text
    • http://galluccifaibano.com/userfiles/file/xurozenerosimasanu.pdfIn PDF document text
    • https://archielectronics.com/userfiles/files/jizotazurivi.pdfIn PDF document text
    • https://marlin-aquarium.ru/ckfinder/userfiles/files/defupajebalupupanigef.pdfIn PDF document text
    • https://tigaintan.com/contents/files/dodasidalo.pdfIn PDF document text
    • https://www.prshots.com/ckfinder/userfiles/files/80462576691.pdfIn PDF document text
    • http://werkschoenenverkoop.nl/images/docman/files/88801502008.pdfIn PDF document text
    • http://peter-crooks.com/userfiles/file/xupizalojaguwid.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138a6ee4e43d---75509023916.pdfIn PDF document text
    • http://abwhopewell.com/uploads/files/diwegafokolazox.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec805000e7---pefimigimotirol.pdfIn PDF document text
    • https://stradatextiles.com/upload/ckfinder/files/sewofirijebegitusuxebiwem.pdfIn PDF document text
    • http://agecarekorea.com/ckupload/files/xanenolofisupezipaso.pdfIn PDF document text
    • http://f1-rennsimulatoren.de/userfiles/file/kaxakotoriwadegezolewib.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=redmi+note+9+5g+india+launch+datePDF 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_off0000b085.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB085 10996 bytes
SHA-256: 56f2495580ac8849c84130b3cdb3ba1c4aab5acbc0c6ad8f0e53fdbd245181db
font_01_sfnt_off0000c9b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9B3 17156 bytes
SHA-256: 8fb7d8da7ea326b8fdf1cc0b87f4c73e1c0473d236f8e72ba83b8c96fd27fb51
font_02_sfnt_off0000f53b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF53B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1