Malicious PDF — malware analysis report

Static analysis result for SHA-256 5dc7d9769e510b7b…

MALICIOUS

PDF

79.6 KB Created: 2021-09-18 23:55:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 900310dd48e88bb6847242ea0f0f8ed5 SHA-1: fcbc2ab473ddccb66723c629f1249e08217b4620 SHA-256: 5dc7d9769e510b7bc56d70e0554ed4f0f220a8056703ce542621a1c0c8db5e64
172 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and numerous external links, some pointing to compromised WordPress upload directories, suggesting it's part of a phishing or malware distribution scheme. The presence of a 'download button' heuristic further supports the attack pattern of luring users to download malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 8

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://ketchas.ru/uplcv?utm_term=convert+eml+pdf+online+free
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140c6f16b0f9---67184832084.pdf
    • https://xn--psg-9lac.hu/files/files/sufubalosojadi.pdf
    • https://proxkimya.com/resimler/files/wuwegu.pdf
    • http://parzenica-bialka.pl/userfiles/files/vikinenap.pdf
    • http://ncdesign.it/userfiles/files/xukatifu.pdf
    • https://taperagi.com/contents/files/44307511121.pdf
    • https://nicklason.se/ckfinder/userfiles/files/40848723392.pdf
    • https://skl.deindrukdemo.nl/upload/files/vegilixojexakas.pdf
    • http://tivatijapan.com/uploads/userfiles/file/9627285056.pdf
    • http://chiari-web.com/ckfinder/optimist/files/86002562491.pdf
    • https://weborder.cloud/userfiles/file///wowubajila.pdf
    • http://asesorgubernamental.com/images/file/vimuvewefagafe.pdf
    • http://getem.eu/files/file/58714318553.pdf
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135756b2e9bc---nazasinafo.pdf
    • http://smepil.com/ckeditor/userfiles/files/baxujebanomoweru.pdf
    • http://www.liveartsaskatchewan.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614101a947c9c---87562187241.pdf
    • https://wheelmartthailand.com/image/upload/File/gorabezoludofemunowe.pdf
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144bdb8df161---nojetivakisudo.pdf
    • http://www.martiusstaden.org.br/js/ckfinder/userfiles/files/reguromu.pdf
    • https://tahuacoop.com/cms_gpadmin2015/sgi_userfiles/userfiles/files/79670318948.pdf
    • http://queensparkview.com/image/upload/File/fofivetawetigoxused.pdf
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614490365726b---15609331663.pdf
    • https://szabobuszrendeles.hu/files/files/15510832083.pdf
    • 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_off0000d670.bin
e0879aacc4e453468f587fb5de658704701fa0840fa66ddb19d2d630ed920b2c
pdf-font-stream PDF embedded font (sfnt) at offset 0xD670 16412 bytes
font_01_sfnt_off000100fb.bin
aa976369fd2d8fa6cd08b4c5859638e4fe8882d7f6ea18e29b84425324a8d151
pdf-font-stream PDF embedded font (sfnt) at offset 0x100FB 10424 bytes
font_02_sfnt_off00011892.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11892 16792 bytes