Malicious PDF — malware analysis report

Static analysis result for SHA-256 163c3aff5d245141…

MALICIOUS

PDF

80.5 KB Created: 2021-09-02 03:27:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f052aaf6437f9b18c311c0775a55eb53 SHA-1: 7081c78003e0c8facef3230f03565fd9d894a2df SHA-256: 163c3aff5d245141b8fba2a156d0c1507f7a321f659cd4471e5db207931e188f
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. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised websites. The presence of numerous URLs, many hosted on disposable domains or compromised CMS uploads, suggests an attempt to distribute malware or conduct phishing attacks. No scripts were extracted, but the overall structure points to a malicious document designed to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 http://marthomaiticherukole.com/userfiles/file/wadamuwareb.pdf In PDF document text
    • http://www.segurosfacility.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16093dbeba080c---21578007349.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/974c471f9f75a4fb7f7fd9e610978e00/bumomagubuvidu.pdfIn PDF document text
    • http://flex-link.cn/uploadfiles/files/32207320657.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e2724d276d5---fizezud.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608121ff34511---mavedixamizevezunu.pdfIn PDF document text
    • http://kurskodkb.ru/page_edit/_samples/userfiles/files/2696093822.pdfIn PDF document text
    • http://www.radanhorse.com/resource/files/42341367282.pdfIn PDF document text
    • https://aimhc.com/userfiles/file/demiwivudurerupet.pdfIn PDF document text
    • http://szamosiszerviz.hu/feltoltott/files/8223897425.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b812213c143---56335034954.pdfIn PDF document text
    • https://vmwarts.com/ecovic/file/nosikuk.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/160d3fde46f6fa---jafof.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/160b340f7e66d5---naxoraxajosot.pdfIn PDF document text
    • http://autoscuolepintozzi.it/userfiles/files/7045630039.pdfIn PDF document text
    • http://nesemlak.com/test/images/uploads/files/36696433383.pdfIn PDF document text
    • https://rubin2000-distribuitorshop.ro/userfiles/file/29263947771.pdfIn PDF document text
    • http://uzks.hr/upload/datoteke/9498256815.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606f691823a11---20387842412.pdfIn PDF document text
    • http://artikos.pl/userfiles/file/70680522873.pdfIn PDF document text
    • http://s-privod.ru/userfiles/file/tavimasutizaj.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/4ff3077a17cc844f9a9dc9cf0e220355/semukomabawolip.pdfIn PDF document text
    • https://fishboat.hr/files/menasotuvidexegodufum.pdfIn PDF document text
    • https://kurtoglumob.com/upload/file/39068219849.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=easy+harry+potter+origamiPDF 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_off0000d40f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD40F 18664 bytes
SHA-256: 04000f6e3c31f0cdb39998e6080283cbcfc5dfc183ed65a08f6f124ae3395c8e
font_01_sfnt_off0001042b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1042B 10644 bytes
SHA-256: 444d6c0684b37b33720b96b650a04a519a74e2167ab66c6e20a891432c24523f
font_02_sfnt_off00011ca2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CA2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1