Malicious PDF — malware analysis report

Static analysis result for SHA-256 40955b83504c0828…

MALICIOUS

PDF

91.4 KB Created: 2021-09-11 00:03:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 46d17759b98212eb79cb60ea805b2950 SHA-1: 48a3103396df1ef29209b3831cf98efabddd06df SHA-256: 40955b83504c0828c97c444222ce030e98aadd1b33343eee84bf69ffa9a548a6
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic and the numerous extracted URLs suggest the document is part of a link farm designed to manipulate search engine results or distribute further malicious content. The presence of many unknown reputation URLs supports this, despite one benign Google feed URL.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://7foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/80960750226.pdf In PDF document text
    • http://lamgi.pl/ckfinder/userfiles/files/vebomomoruleluzezav.pdfIn PDF document text
    • http://gemmacapitalgroup.com/foto/file/pasuxubupowuri.pdfIn PDF document text
    • https://literie-depot.fr/UserFiles/file/pokemitivuziz.pdfIn PDF document text
    • http://soluzionebenessere.eu/userfiles/files/28183676910.pdfIn PDF document text
    • https://sudhirsachdevaclasses.com/ci/userfiles/files/83884966549.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a000ca18d9---fagafu.pdfIn PDF document text
    • http://unionnutritech.com/upload/files/34216203013.pdfIn PDF document text
    • http://apnschool.in/singhania/downloads/file/14981491384.pdfIn PDF document text
    • https://koetec.com/home/~ptow/public_html/ckfinder/userfiles/files/vupobavoma.pdfIn PDF document text
    • https://truckforceone.eu/upload/editor/file/96435290354.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/c0ca5cfc659dbf5d1ff1615cdd2cb22e/54846626052.pdfIn PDF document text
    • https://rintrans.com/files/metutefet.pdfIn PDF document text
    • http://munnartourism.com/uploads/file/vesesujofakeratirunifag.pdfIn PDF document text
    • http://istanbulballoons.com/ckfinder/userfiles/files/8684807675.pdfIn PDF document text
    • http://rayanchem.com/d/files/8421479018.pdfIn PDF document text
    • https://skykharchono.mn/editor/files/denumakujizivevakukerubo.pdfIn PDF document text
    • http://raylutickenterprises.com/userfiles/files/71756372794.pdfIn PDF document text
    • http://chanhungcorp.com/images/uploads/files/64492733005.pdfIn PDF document text
    • http://eastendmediation.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/46222659511.pdfIn PDF document text
    • http://awarelaxcentrum.cz/user_files/file/buriwofovorikokuv.pdfIn PDF document text
    • http://www.louisianarebarcontractor.com/editorimg/file/10394940263.pdfIn PDF document text
    • https://weddingitaly.jp/images/file/15421011352.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=andrew+ng+machine+learning+pdfPDF 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_off0000f9df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9DF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000111f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111F1 20160 bytes
SHA-256: 7db7cbb16fed064a107073d324fcf4c87fa2755aef1c370db3c51412a20a91ef
font_02_sfnt_off000146ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x146AE 10748 bytes
SHA-256: 7d8d50c539b7061789e2e0371e335979eec5645548d09767e3e32bff2b2696fb