Malicious PDF — malware analysis report

Static analysis result for SHA-256 892d1432a92bcb0c…

MALICIOUS

PDF

84.1 KB Created: 2021-09-16 07:25:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 50f5d7d7a3e0e78a696095f1388adff8 SHA-1: 812b568ebb0be98c156ebf168549a75cd816a4d8 SHA-256: 892d1432a92bcb0c50aad672e113230dc354d3d7ae7e482acaee3888d4b63f6c
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS upload directories, suggesting it's used to distribute or host malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/16138a62231d54---98040438783.pdf In PDF document text
    • https://thaiahpa.com/flash/files/nasesixugupipavogibiz.pdfIn PDF document text
    • http://wwstationery.com/files/file/wizofurarirelejuvupofed.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134a5d9e00e3---sokegesewufomisuvivu.pdfIn PDF document text
    • https://aitalk.vn/upload/files/32160626401.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614048d999799---lepidari.pdfIn PDF document text
    • https://ofcourselc.com/admin/uploadsfile/64591664945.pdfIn PDF document text
    • http://dallapietamarchisio.it/userfiles/files/lekiwifenumepawefunuzebo.pdfIn PDF document text
    • http://stowarzyszeniemalyksiaze.eu/img/upload/files/wodebilifanuxok.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161423aab153cd---rubizeteti.pdfIn PDF document text
    • https://hoangvan.vn/wp-content/uploads/files/zekimalole.pdfIn PDF document text
    • http://oldadmin.k12cart.com/media/files/64340181168.pdfIn PDF document text
    • http://studiodugnani.it/userfiles/files/476553033.pdfIn PDF document text
    • http://alajwakh.com/uploaded_files/userfiles/files/vuwibebusenuxinewigibon.pdfIn PDF document text
    • https://pnvvr.ro/userfiles/file/kamapoxanef.pdfIn PDF document text
    • http://chip-chup.hu/upload/file/fefunasudivexatome.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614294dd129b0---41558814153.pdfIn PDF document text
    • http://heatexchangersolution.com/upload_fck/file/2021-9-5/20210905084709235508.pdfIn PDF document text
    • https://sharks-cz.cz/images/file/3808419165.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161384e518b2f1---59776054371.pdfIn PDF document text
    • https://anjingliar2.com/contents/files/nuvimu.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614169d6eb322---kekofapiwo.pdfIn PDF document text
    • https://verlauf-ekb.ru/admin/ckfinder/userfiles/files/87617212261.pdfIn PDF document text
    • http://dongphat.net/upload/files/risanoburovowuri.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=watch+antebellum+online+freePDF 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_off0000e37b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE37B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fb8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB8D 18168 bytes
SHA-256: 3d337d60481d8704a694a92e6ced2d1a1f27b840a65df9552f546c16c9b425bc
font_02_sfnt_off00012a9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A9B 10664 bytes
SHA-256: 2cdc06fee72575e0c4c81e2be49d2187616e35e3b25699c5f92a995180327024