Malicious PDF — malware analysis report

Static analysis result for SHA-256 73a364e57799283e…

MALICIOUS

PDF

101.8 KB Created: 2021-09-01 12:17:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5b00423c93136fc01ae67db95408774a SHA-1: 145f3b54c1820aa4ce702dca90814ef3f0975e5b SHA-256: 73a364e57799283e4167be6f262cc9e335cbd2dd0288e58736c6a286ea9e97b4
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to external websites, including compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious sites for phishing or further exploitation. The document body is heavily obfuscated and unreadable, providing no direct content-based clues.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://hciclerp.com/asset/uploads/files/memekojedu.pdf In PDF document text
    • https://makenie.com/upload/files/55823476456.pdfIn PDF document text
    • http://nfraccon.org/userfiles/file/12265217379.pdfIn PDF document text
    • https://www.vedaaz.com/wp-content/plugins/super-forms/uploads/php/files/921576ae469a1478fbf7a7176a505501/23294828779.pdfIn PDF document text
    • http://chongthamnguoc.vn/img/files/betetuwakuboxebok.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e01f93e35b---rupikifawapagibimixog.pdfIn PDF document text
    • http://castel.lu/userfiles/files/kosegu.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac95dbf41c0---55569414483.pdfIn PDF document text
    • https://shen-su.eu/gfx/userfiles/files/rozalono.pdfIn PDF document text
    • http://shengnabei.com/uploadfile/file///2021081008310420.pdfIn PDF document text
    • https://ilc.ua/wp-content/plugins/super-forms/uploads/php/files/cftkl1188mg376fl0cse11ram5/74737023094.pdfIn PDF document text
    • http://bestorkate.com/uploads/ckeditor/files/21229167884.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/lqr1td4f0vmaeqhjaqhlgpv1t5/rutabusojimojutuvidesoli.pdfIn PDF document text
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bc0f289bd9---51501428517.pdfIn PDF document text
    • https://volpatoebrum.com.br/_common/admin/scripts/ckfinder/userfiles/files/90307851730.pdfIn PDF document text
    • http://begemot-rus.com/uploadfiles/file/2021060523500173499.pdfIn PDF document text
    • http://agrion.org/upload/fichier/diforimo.pdfIn PDF document text
    • http://abarappresentanze.it/userfiles/files/vokijidavatuguzo.pdfIn PDF document text
    • http://villaelen.it/userfiles/files/wuxumovukoxeg.pdfIn PDF document text
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b0fc7165932---kumowijupifasumodode.pdfIn PDF document text
    • http://esebtekstil.com/resimler/files/sedokobowoxabega.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=quantum+computing+and+cryptographyPDF 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_off000126ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126BA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00013ed1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13ED1 10888 bytes
SHA-256: 3daae9929b9155ecf2d392f3621ff287fee9cbe59b4f84ab1153203ebb3bd674
font_02_sfnt_off000157ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x157AC 19316 bytes
SHA-256: 9cbe65657721c88dd585da08b36ac02889a3154a959c93ff9343f3978018b8db