Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8a2053093f2e1ae…

MALICIOUS

PDF

66.8 KB Created: 2021-05-10 06:16:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: b1480a163ebdf4ebb938612922430d0d SHA-1: e6c9ac3cce7a6aab3f9f2fef3579f68ad095fbf5 SHA-256: a8a2053093f2e1aec998722dfd7f2a528b5302c9825d11da3a43187b96f13c11
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to redirect users to malicious content. The presence of these links and the overall structure strongly suggest a phishing or malware distribution attempt.

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://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/16070d1d834927---vunamevulamatugew.pdf In PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609045880f0be---22360493615.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1607cf1fbf02b1---69016755933.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081e3399aecf---99275733050.pdfIn PDF document text
    • https://otelnamore.com/wp-content/plugins/super-forms/uploads/php/files/7fae4a7faafd9ee5b2d641c8dc6dbc97/lesatovaw.pdfIn PDF document text
    • http://rolmech-strzelno.pl/Upload/file/juxofolovot.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1608e365710880---fanusurikufomubuz.pdfIn PDF document text
    • https://laser-arena.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16077b673dd6b7---90663285165.pdfIn PDF document text
    • http://alibabashipping.com/userfiles/file/28656169753.pdfIn PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/7b186e111fd85dc6e917b31277f4d6a5/73627275635.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/d7427e5f22593d4d764825c005f865f1/8846688687.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/16088165f52661---ziwabafuxetibuguje.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/12717d6a2d52f02af046d4965e6c7161/nomogifigika.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/vgi5cjcslva0ftvm86q618nbh4/96428454147.pdfIn PDF document text
    • https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/09a409d7bbf7f19c1cc8ea7ab65bc7df/gadirubetedefosilosewobuk.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097c0e43d2b4---vifirikoka.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/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=adding+and+subtracting+fractions+unlike+denominators+worksheetsPDF 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_off0000c716.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC716 5720 bytes
SHA-256: b8b598b2199d24b97bcb17c50db5a36ecc382eccb111e3c2a8ad4f9ee53af4b0
font_01_sfnt_off0000da77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA77 10340 bytes
SHA-256: f5eca4759cba6ef05bdad2152ec753b1065c761c80e46f239e228ab2ce04e5b5