Malicious PDF — malware analysis report

Static analysis result for SHA-256 a73628434fcd28ff…

MALICIOUS

PDF

69.5 KB Created: 2021-09-28 21:51:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3b6a1b8327bf2b813c1ecaab70692ba4 SHA-1: b3641a70c750ff9c052a4fb8ed1917941de6859f SHA-256: a73628434fcd28ff70166e6878f432a0c7f93630bab4de662a5250cf6164ddab
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs, many of which point to compromised or disposable hosting. Heuristics indicate it functions as a link farm, with a high ML score and ClamAV detection confirming its malicious nature. The primary goal appears to be redirecting users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://auxerretv.com/content/public/file/sasofufemetunuseja.pdf
    • http://bannhuaduong.net/upload/files/rubiri.pdf
    • http://studioesflores.pl/obrazy/file/13346916444.pdf
    • http://urgentcarepb.net/userfiles/file/67644423420.pdf
    • https://www.frontiermea.com/sites/all/libraries/ckfinder/userfiles/files/xagovibiziwekugavefiz.pdf
    • http://boxshop.mn/userfiles/files/82719139425.pdf
    • https://derechosenred.org/aym_image/files/luvejupilemozixe.pdf
    • https://novitas.ro/files/36882658209.pdf
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143b94280a7d---xufufapababefadedolol.pdf
    • http://allefrgycg.news-read.com/upload/files/31298947313.pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614c348eb642e---xudabamubeduwojas.pdf
    • https://aspit.ro/imagini_ws/rojirigosaru.pdf
    • https://www.bramfordgc.co.uk/ckfinder/userfiles/files/dezaxadusa.pdf
    • https://vayamcs.com/content_files/files/rakavekepiwaxus.pdf
    • http://rimini-portal.de/bilderarchiv/file/15911213825.pdf
    • http://ideviceplus.be/app/webroot/files/userfiles/files/6173038552.pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161402cce2a425---31468707804.pdf
    • https://svltv.in/userfiles/files/kewij.pdf
    • http://www.tlo.ntou.edu.tw/ckfinder/userfiles/files/dewopubagulopunonowu.pdf
    • https://safrano.pl/userfiles/file/18061914488.pdf
    • https://art-eria.pl/mandarynka/pliki/files/zevatesukod.pdf
    • http://hardiebase.com/uploads/assets/filefile/11812267160.pdf
    • https://theshamrockpublecco.it/file/67230390067.pdf
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16146d540a98e7---bofozisazurofivowowexo.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=happy+words+beginning+with+e
    • 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_off0000afdf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xAFDF 16792 bytes
font_01_sfnt_off0000c7f1.bin
8ac9dbee60d11c37043c4e7f1e8efc80e3e1fd016bd6481d9596890704e8f302
pdf-font-stream PDF embedded font (sfnt) at offset 0xC7F1 15744 bytes
font_02_sfnt_off0000ef83.bin
1d174fdd7c9e16f4ea827432db161742ffebd81f79973fd1a79e4490ca24e3c0
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF83 10956 bytes