Malicious PDF — malware analysis report

Static analysis result for SHA-256 f541f1242bdc04be…

MALICIOUS

PDF

74.9 KB Created: 2021-09-07 13:28:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: ebcaf05dca6ef02bc6bbc81ed4c78f1c SHA-1: 327e250fd38572ae28ff33053fbed1ac4c0689af SHA-256: f541f1242bdc04be82074f424cb600c1d7252900fbc2a50cff90a303cc89c8dc
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Several heuristics point to the PDF acting as a link farm, directing users to compromised CMS upload storage and disposable hosting sites. These URLs are likely used for phishing or to serve further malicious content.

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://bydnjl.com/userfiles/files/20655451302.pdf In PDF document text
    • https://fultoys.com/userfiles/91667006538.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae5f4d6867d---62857359442.pdfIn PDF document text
    • http://am-assets.com/aom/magnolia/userfiles/file/bifexabuxaradurejujabe.pdfIn PDF document text
    • http://staging.impactredevelopment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d8fb09320f---76367752092.pdfIn PDF document text
    • http://techbico.vn/uploads/image/files/fogutixikanotigomusa.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/6a6e9a3b22a2a7e2c0e8d423b738308e/43919016652.pdfIn PDF document text
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/fujfs18797gpjd0oh6583tmimg/toforadid.pdfIn PDF document text
    • https://turkuazhost.com/calisma2/files/uploads/39774187317.pdfIn PDF document text
    • https://transpack-krumbach.de/_upload_bilder/_filemanager/file/difosawofapatubuludi.pdfIn PDF document text
    • http://www.assignproject.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609aaef8d5d42---vivexuxevotomevap.pdfIn PDF document text
    • https://cald-lighting.com/wp-content/plugins/super-forms/uploads/php/files/fc2cb638b7a08177189e3c1df4d2d31c/kakuriboboko.pdfIn PDF document text
    • http://copy2d.com/ftp/image/file/16237783409.pdfIn PDF document text
    • http://retroldn.com/userfiles/file/91908648072.pdfIn PDF document text
    • http://amoy-art.com/Upload/file/zobugasulukozenan.pdfIn PDF document text
    • http://luxcottage.ru/stroykamen/userfiles/file/98948399013.pdfIn PDF document text
    • http://xn--h1agcmh.com/ckfinder/userfiles/files/duratinafonume.pdfIn PDF document text
    • http://artecgroupservices.com/imagenes/file/potozawawa.pdfIn PDF document text
    • http://jtipartner.com/ckfinder/userfiles/files/memilevelisar.pdfIn PDF document text
    • https://rajakeempat.com/contents//files/sozimurusokixat.pdfIn PDF document text
    • http://hwayinn.com/image/files/20210603_024359.pdfIn PDF document text
    • http://doks-films.com/pcms/content/file/86365605055.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=bascule+rst+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://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_off0000c237.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC237 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA49 16952 bytes
SHA-256: b92bcea7f40a82194140fa5843a445080e7524372856827be2e158cb0cea6130
font_02_sfnt_off000105f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105F3 10452 bytes
SHA-256: 843d7b9958c2b95cff7b6e9b74bfdb712f1c28c5854fbe67bd1e8b70c6c10f40