Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b935472eff2914d…

MALICIOUS

PDF

65.4 KB Created: 2021-06-23 21:53:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: 035df691a7ec19fd66e4dafb359a81b5 SHA-1: 9b035d9ae394660e6eee713fd82201456ac738fd SHA-256: 3b935472eff2914de2bd3aed14fe5a53ab75cbf430316b77512acc499541fcd2
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • 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 http://fsoa.cn/userfiles/file/61623007408.pdf In PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606f9170a60b4---texalivinimo.pdfIn PDF document text
    • https://serka.com/serka/upload/files/wosulep.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ca052e79bc6---fanalokegavukamepozov.pdfIn PDF document text
    • https://centrosteadycam.it/wp-content/plugins/super-forms/uploads/php/files/4e28f3850ddc1c35a5837f0d83c52297/rogorisinig.pdfIn PDF document text
    • http://franklinbristerharveyfamily.com/clients/a/a8/a8910385c57dfddac3c6311e2bd1422e/File/gatilowemigegetegag.pdfIn PDF document text
    • https://aterhesseg.com/up_image/file/95665659584.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1608731ba7db69---58308987110.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607529e7d417b---nawefaxewe.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088c1e84f303---26497606850.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8a8efe9256---wozatininebuxeruji.pdfIn PDF document text
    • http://profisystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606fa36459339---89404683794.pdfIn PDF document text
    • https://cafesca.org/ckfinder/userfiles/files/dupotupamifopoxu.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/d09333359cd1b20f7762aa4c856bef74/67777232478.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160747f84d2b73---julipubuvad.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=husserl+logical+investigations+volume+2+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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000becc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBECC 5628 bytes
SHA-256: 621eca0e5f2490d20dcb1f422c7985582a80a0876b33d82dd621e300adcd61a0
font_01_sfnt_off0000d1ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1EC 11492 bytes
SHA-256: f8565083abe0915b0e1a89e5e50274b98a154618a0fb07e7ecb23d78bb7686bf