Malicious PDF — malware analysis report

Static analysis result for SHA-256 33845470963fcb4b…

MALICIOUS

PDF

75.7 KB Created: 2021-06-20 23:47:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 5cf08dca99952a1444a5292f154ae0e8 SHA-1: 0f0fbcd73ee2e378e901acca276bdcb0640a7104 SHA-256: 33845470963fcb4ba0dd89d8a2e3ed575e6f736a3a9692a64a0a1c5152451db5
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the document contains a link farm pointing to compromised WordPress upload storage and disposable hosting, suggesting an attempt to redirect users to malicious sites. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the URL analysis.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bdc6c985b85---sepezemubowekuv.pdf In PDF document text
    • https://www.duffylighting.com/wp-content/plugins/super-forms/uploads/php/files/e444de01e7c14a222fd453717a4de269/pepam.pdfIn PDF document text
    • http://wskinbody.com/data/boardData/files/19701007241.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078a38035ad3---81786479594.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607e5f29017fb---26956762616.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/619acfbc456bafab99108b5f526ea102/zanelodesibiwerajutiwita.pdfIn PDF document text
    • https://clubesolbra.com/uploads/files/59582129559.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/e72811ec36ea7e80c2e8bbb52bc7e187/degurenu.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/de5812494368280fcee01fd6b1ae299b/46697277682.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077def42786b---32307261990.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/1608593f8d2f64---92660256157.pdfIn PDF document text
    • http://irina-beha.com/ckfinder/userfiles/files/vukininolawesuzupuf.pdfIn PDF document text
    • https://akproauto.net/nbloom/fckuploads/file/41872549302.pdfIn PDF document text
    • http://hanasushimenifee.com/uploads/files/buwodipajux.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/744aa4af70ba2ca6034d0d9464aca1fb/duguso.pdfIn PDF document text
    • https://carea2plus.com/wp-content/plugins/super-forms/uploads/php/files/aa1331179141f6a8b6816c05e8895534/ralegolarupesipodilezex.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/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=qui+que+dont+ou+practicePDF 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_off0000e2a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2A6 5044 bytes
SHA-256: 30e202053dc47177f5076a3196d423137c4bdd6ff34cda3872bcdeef4a73354e
font_01_sfnt_off0000f3d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3D9 14436 bytes
SHA-256: 9bb79cba5241834f22094f7d4ed49367db1fd7fadcc1c384b3d2550e5ffce54d