Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6353fab9fe83e52…

MALICIOUS

PDF

104.2 KB Created: 2021-06-28 05:55:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5979e6827bccfae6260ae6cb4b9a25b3 SHA-1: 9280dfd993725b923884b1d17a459e38117ffed7 SHA-256: a6353fab9fe83e5253bfcee8c794632a65c5b83230969bccebed1c0b8cac6f68
156 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, specifically as a phishing trojan. It contains numerous links, many of which point to compromised WordPress sites utilizing the 'formcraft' plugin for file uploads, suggesting a link farm designed to redirect users. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9934

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/160bfb034d9e23---19435869656.pdf
    • http://www.kammerpop.de/files/file/tetovemivuteximawifama.pdf
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160cf53c608ba2---14621691140.pdf
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609837aff0821---46573359633.pdf
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a33265dc919---sisukejutewewoxewasav.pdf
    • http://perlawarmii.pl/userfiles/file/rokizutubag.pdf
    • https://cruiseship.cruises/wp-content/plugins/super-forms/uploads/php/files/o834a13ndjshcmq5hphont5tfe/95653529218.pdf
    • http://22743333.com/userfiles/files/zugiredijotalukabiwu.pdf
    • https://ipcare.nl/wp-content/plugins/super-forms/uploads/php/files/e4gkqj10ajvqbdfff0p94nuda5/21168613962.pdf
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa50b93f778---jajoruwefokuvafuvij.pdf
    • https://soechi.com/userfiles/file/97269995741.pdf
    • http://bjhtdszdh.com/v15/Upload/file/2021628918423049.pdf
    • http://birnagarcollege.in/userfiles/file/wufezolonifogalif.pdf
    • https://him-home.ru/wp-content/plugins/super-forms/uploads/php/files/45c5ff0de1b61787b8b0b30fa20a8a0b/jokafubapimosojokipaleziv.pdf
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/a43mqko6n6g0s334cn7c57vek6/11033277297.pdf
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f4c8ce5e0b---bovagubijav.pdf
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/rvf7e6ttdvsd1tqm3c9j3gd958/memobaz.pdf
    • http://kameleonhastanc.hu/files/file/87117405132.pdf
    • http://jjburgerut.com/uploads/files/talosore.pdf
    • http://nusratali.com/userfiles/files/nogabafubusavadopiguza.pdf
    • http://radissonhoteltraining.com/userfiles/file/88535343738.pdf
    • http://www.atrium-tuiles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5c282e0f89---dorerejati.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=disenthrall+meaning+in+english
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000139c4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x139C4 16792 bytes
font_01_sfnt_off000151db.bin
36abb751b2d079bc1825038536e2abdea4ed9953bdde4018b96a6e3a929c2884
pdf-font-stream PDF embedded font (sfnt) at offset 0x151DB 10436 bytes
font_02_sfnt_off0001694f.bin
ec34528ed02b5769dc3ef636a371a6ce71c87d543cb932b7626da134a4deeef7
pdf-font-stream PDF embedded font (sfnt) at offset 0x1694F 15868 bytes