Malicious PDF — malware analysis report

Static analysis result for SHA-256 237233c3569a8e81…

MALICIOUS

PDF

73.9 KB Created: 2021-09-20 05:10:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: bac2e7ad01a2d1645872c2dfc5c36b92 SHA-1: acbd2505a34f29fa92b2fdfbae92ff975dfb234b SHA-256: 237233c3569a8e81d2bbdba3c97ad5c87df1a225cc19deede593c9f624d87303
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It functions as a link farm, containing numerous URLs pointing to compromised CMS uploads and disposable hosting, likely to lure users into downloading further malicious content or engaging in phishing activities. The presence of multiple external URIs and link farm heuristics strongly suggests a phishing or malware distribution vector.

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 https://ketchas.ru/uplcv?utm_term=carruthers+organic+chemistry+book+pdf PDF link annotation
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/be0533df9073d1dc2d1b412329fa09e9/3542174522.pdfIn PDF document text
    • https://poulinstrapscan.com/userfiles/file/tifimesiguxujokikadanapeg.pdfIn PDF document text
    • http://vipacademy.org/userfiles/file/zimazaj.pdfIn PDF document text
    • http://kondicionery-vidnoe.ru/upload_picture/file/wagowevuwobesusulu.pdfIn PDF document text
    • http://bukvoznaika.ru/ckfinder/userfiles/files/35184499435.pdfIn PDF document text
    • https://vishalahospitality.com/ckfinder/userfiles/files/44267887015.pdfIn PDF document text
    • http://iberryhomemade.com/userfiles/files/47274606973.pdfIn PDF document text
    • http://fw-simple.com/uploads/files/40676445440.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613abe9916f0c---76913261133.pdfIn PDF document text
    • https://yuktogel.com/contents/files/wokafobebol.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/478472afe6844cd88eb20c3651a2c4b9/53686320488.pdfIn PDF document text
    • http://aodaiminhhanh.com/app/webroot/uploads/files/fesexuzofov.pdfIn PDF document text
    • http://theofficeplus.com/userfiles/file/wefaxozawebeguzelejukupi.pdfIn PDF document text
    • http://lmnn.ru/userfiles/file/23619255839.pdfIn PDF document text
    • https://fullprotec.com/ckfinder/userfiles/files/jaxuximevinufururo.pdfIn PDF document text
    • https://ntpuvoice.com/ckfinder/userfiles/files/63125547925.pdfIn PDF document text
    • https://educationindiajournal.org/ckfinder/userfiles/files/sapoketukavoguribajolop.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/87793518764.pdfIn PDF document text
    • http://zkojicin.cz/userfiles/file/42773596025.pdfIn PDF document text
    • https://yomadesign.com/userfiles/Proj_Name/files/muxozinedaga.pdfIn PDF document text
    • http://designpavelzapletal.cz/files/file/nuverazojovutumelemiso.pdfIn PDF document text
    • https://assignmentmart.com/ckfinder/userfiles/files/gilovewejifejafowifaxo.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_off0000bc4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC4A 11500 bytes
SHA-256: acdcb9f4ff2aba36ea757a48a3f61442018c36f1fd8fafa95bf34543cb442ef9
font_01_sfnt_off0000d6f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6F5 16324 bytes
SHA-256: e3547eb26da4fd3335752017d2be868f9bfc6f25ca93c1ab7528a5cd5d5bdd9a
font_02_sfnt_off0001017e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1017E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1