Malicious PDF — malware analysis report

Static analysis result for SHA-256 35f98bc8af9173e3…

MALICIOUS

PDF

79.8 KB Created: 2021-09-16 15:05:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 461939a58ee67037b5ca608a17706b3d SHA-1: e9732f94a3db6376fb5d2953d9a04de059211294 SHA-256: 35f98bc8af9173e30bf0135f4a27fbac34db76091d18ec76c5df043fb533557f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs hosted on potentially compromised or disposable domains. These links likely lead to phishing pages or further malware downloads, aiming to exploit user trust.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • 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.
  • 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://chcial.ru/uplcv?utm_term=portal+365+login+admin PDF link annotation
    • http://blccy.com/userfiles/files/fevena.pdfIn PDF document text
    • https://www.aicsmindia.org/ckfinder/userfiles/files/72120891480.pdfIn PDF document text
    • https://www.southdownscellars.co.uk/ckfinder/userfiles/files/nenilafetusugexixivumezum.pdfIn PDF document text
    • http://www.moyekolodin.com/files/42142668900.pdfIn PDF document text
    • http://italy-ex.com/images/blog/file/womuxefuj.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1613221e8d2aa4---53044367391.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131f87e72a1b---xirutugibeku.pdfIn PDF document text
    • http://huanghels.com/filespath/files/20210916080610.pdfIn PDF document text
    • http://zygzak.eu/foto_dane/wysiwyg/File/kezezikit.pdfIn PDF document text
    • https://sibois.eu/userfiles/file/pufinibakizolaxofujapoku.pdfIn PDF document text
    • https://villanakarin.com/userfiles/files/rugolularep.pdfIn PDF document text
    • http://asiadomainstore.com/userfiles/file/90718775201.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16131932a30b6c---8105731657.pdfIn PDF document text
    • http://fohow77.ru/upload/file/gejoji.pdfIn PDF document text
    • http://warwick-ems.org/userfiles/file/69676739227.pdfIn PDF document text
    • https://ihappywash.com/uploads/files/202109132048167177.pdfIn PDF document text
    • http://soleilboo.com/images/uploads/files/bufosodisoxeg.pdfIn PDF document text
    • http://strandedtattoo.com/file/vorodimotatepak.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee9b5d13e4---84175135320.pdfIn PDF document text
    • https://100tmt.com/uploadimage/files/20210915225107.pdfIn PDF document text
    • http://ekotop.eu/userfiles/file/24877172032.pdfIn PDF document text
    • https://www.baust.edu.bd/app/webroot/ckfinder/userfiles/files/39019644173.pdfIn PDF document text
    • http://punaide.com/userfiles/files/24719541223.pdfIn PDF document text
    • http://american-security-inc.com/assets/ckfinder/userfiles/files/36996112191.pdfIn PDF document text
    • 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_off0000cfd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFD1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e7e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7E3 18656 bytes
SHA-256: 346887cc7e0978ce5c978495ca5a8281bbe860e7a7a7cd6f4e6777da8722dac8
font_02_sfnt_off00011932.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11932 10768 bytes
SHA-256: d5c126a3a841c9e6241086d588814903071dbe82218ac2c895f74f59fc25a28e