Malicious PDF — malware analysis report

Static analysis result for SHA-256 55c451c9667f8883…

MALICIOUS

PDF

81.7 KB Created: 2021-09-11 21:33:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b36c5b54992cdac61feaae250ba33b32 SHA-1: 7179eb06381ccf82ead59a39b4780fed492eb367 SHA-256: 55c451c9667f88835d60b81cb1779b6da5da86a5763c36554f0b1d9b25f792d7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple heuristics indicating it is a link farm designed to redirect users to potentially malicious content, specifically a download for a game. One of the extracted URLs points to a compromised WordPress upload storage, suggesting a method for hosting malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://hzeiger.com/userfiles/file/gejexomuz.pdf In PDF document text
    • http://ambulanceservice.pl/userfiles/file/fudarewovidogisuvivejake.pdfIn PDF document text
    • http://jvcc.cn/ckfinder/userfiles/files/210906202859795569x66ee.pdfIn PDF document text
    • http://letresorellebio.it/userfiles/files/lapifetawerikimajil.pdfIn PDF document text
    • https://immo-cjeanpaul.lu/userfiles/files/50686946434.pdfIn PDF document text
    • https://resonanceacteurs.nl/userfiles/file/fojanuvajunusuzorixebini.pdfIn PDF document text
    • http://energyexcess.com/userfiles/file/43837288354.pdfIn PDF document text
    • https://accu-split.com/userfiles/files/62845512041.pdfIn PDF document text
    • https://skywaynepal.com/userfiles/file/kaxitenukabu.pdfIn PDF document text
    • http://pensjonatagat.pl/userfiles/file/15404398888.pdfIn PDF document text
    • http://xn--80aaaaaikdebj9ccf1ayja1b5a3q.xn--p1ai/ckfinder/userfiles/files/79364263219.pdfIn PDF document text
    • http://wirheiraten.de/images/file/83730917866.pdfIn PDF document text
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161312c4a1e13a---vanediwewajesofowakaziki.pdfIn PDF document text
    • http://ilkjv.com/Images/Media/files/nafose.pdfIn PDF document text
    • https://ocw.tw/uploads/files/reneboxogonisarawarivi.pdfIn PDF document text
    • https://hamayeshniroo.com/shop/file/tuxikoritagezosupibu.pdfIn PDF document text
    • http://grandviewgroupresort.com/upload/files/nomiduk.pdfIn PDF document text
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/5dc1352783dff8c16bcf204c431b0a43/26888715598.pdfIn PDF document text
    • http://eskuvotoszkanaban.hu/editor_up/fulexigubazewewadelix.pdfIn PDF document text
    • http://jl-vacuum.com/upload/files/mufejanugapar.pdfIn PDF document text
    • https://bodymart.in/ckfinder/userfiles/files/ximokesikerad.pdfIn PDF document text
    • https://radmangroup-ye.com/rgfiles/file/95416040586.pdfIn PDF document text
    • http://phanmemerp.vn/attachment/files/21846033592.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/160kd1n6cmv8h4a0p7rk68v0m7/zonedodesatolafed.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=download+game+gta+san+andreas+apk+gratisPDF 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_off0000d7e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7E5 10916 bytes
SHA-256: 59477fbb661590e7083c284d24c0274240f6a4121a7f901bfdec48dbc7c01033
font_01_sfnt_off0000f0fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010910.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10910 18292 bytes
SHA-256: 1bfdef27939cd7155c897e3d84e59396eb1d9a208ecdbc4dc6e3a88ceb80ec8b