Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7f3d3c9a057672b…

MALICIOUS

PDF

72.5 KB Created: 2021-05-18 05:23:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: 345488582df9d1386d18a78cccdb0136 SHA-1: d224b6c6387e8a7222567ae2f2c86124b8d0b15c SHA-256: b7f3d3c9a057672bff3641418f89ef02e6fdd4123917133f0faa1e0b76904945
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to compromised websites, many of which are hosted on disposable domains or use WordPress upload vulnerabilities, suggesting a link farm or phishing lure. The PDF document body is heavily obfuscated and unreadable, but the presence of external URIs and the overall structure point towards an attempt to redirect users to malicious content.

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://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c659d7fb92---41157526537.pdf In PDF document text
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609b187964e94---49669554816.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/asb1e7ttd89f3opcthpqd61cf0/69854018639.pdfIn PDF document text
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/po5ae3rp2o0l65tei45vnom9es/juxalutozi.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/682943f57ea62df376375562685eb484/59928650358.pdfIn PDF document text
    • http://arcomproltd.com/userfiles/file/fubuxofufevafigup.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/2some81ar9mr0noidsb0am5tjl/24219780131.pdfIn PDF document text
    • https://broadstripe.com/wp-content/plugins/super-forms/uploads/php/files/3b318a3cb2409b53ce3c3a0f6f1ed979/43888687908.pdfIn PDF document text
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/e463ef74697bf8d5286c51133406721c/rasizemubavu.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fc5d2f36aa---80020774592.pdfIn PDF document text
    • https://gdr.co.il/wp-content/plugins/super-forms/uploads/php/files/e1ab616c22bb568a12e08132b12d114d/jomumemam.pdfIn PDF document text
    • https://www.stjohnhomelessshelter.org/wp-content/plugins/super-forms/uploads/php/files/1422d78ed9a68d56c233521c6a0a69d6/66486248222.pdfIn PDF document text
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/bb2f47dd56f7e4ae17dbcc3d8077cba5/19175561597.pdfIn PDF document text
    • http://musorcentrum.hu/files/article/file/61286577128.pdfIn PDF document text
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/f972806fc2f9cf4651831561205d20e5/zufavozupupovavunur.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/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=transform+categorical+variables+to+numeric+rPDF 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_off0000db29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB29 5352 bytes
SHA-256: 79a17a82a7fcce46c7b3bbe99209bdebebfd15fb787946beb9942c4e1fdec0d2
font_01_sfnt_off0000ed52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED52 12036 bytes
SHA-256: a234968329d64812bfa382330846daa4dc973443b7df420d290d04331cb3eef9