Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5cb653c558fb093…

MALICIOUS

PDF

74.1 KB Created: 2021-09-26 11:03:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 9aaa2e4941485b5f07f33df485c1f68c SHA-1: c8ef5a65751a94397272b31a37b8fa77968bca1b SHA-256: a5cb653c558fb093bc4ca3f44790d552d47c7007f3f6c32ae18e130e13deddd9
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the heuristic firings support the conclusion that it's part of a malicious campaign. The primary goal appears to be directing users to external, potentially harmful, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

Heuristics 5

  • 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://wastran.ru/uplcv?utm_term=big+brother+season+22+episode+1+putlocker PDF link annotation
    • https://jmcoverseaspvtltd.com/uploads/files/25816452305.pdfIn PDF document text
    • http://ccadl.com/files/20210913095247.pdfIn PDF document text
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/kinivateripa.pdfIn PDF document text
    • http://mspchicagolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/raduleweda.pdfIn PDF document text
    • http://timnhanhonline.vn/upload/files/mexile.pdfIn PDF document text
    • https://oxi-dental.ro/imagini_ws/60915762411.pdfIn PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/a3vknqfgv605bqrn57h3me7nc7/renufe.pdfIn PDF document text
    • http://uptownfallschurch.com/uploads/files/97604562997.pdfIn PDF document text
    • https://hexema.com/FCKeditor/file/radaxezoxarozipo.pdfIn PDF document text
    • http://x-site.by/upload/editor/files/xawubokireweduwi.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135eaf24e683---46994160539.pdfIn PDF document text
    • http://bdnchem.com/upload/files/dubetewobofazunovajoz.pdfIn PDF document text
    • http://korean-school.hu/hangul/userfiles/file/jasisogagajikafaxume.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d0bea9ba32---41799809152.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/60097607873.pdfIn PDF document text
    • http://www.painters-restaurant.com/userfiles/file/gaxisejejuw.pdfIn PDF document text
    • http://sztarmedia.hu/_user/file/sanilagoxugapupane.pdfIn PDF document text
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/qmp2i7ah91796nvmldardvf111/85969141547.pdfIn PDF document text
    • http://aardbeienfeesten.nl/uploadimages/files/pusot.pdfIn PDF document text
    • http://thingsantiquesla.com/userfiles/files/91782211398.pdfIn PDF document text
    • https://arab-hams.com/Ups/files/minadu.pdfIn PDF document text
    • http://www.examnotice.in/uploads/files/zuvilusadupujabajizisatex.pdfIn PDF document text
    • https://huaku3c.tw/uploads/files/202109021904561138.pdfIn PDF document text
    • 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_off0000b70a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB70A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF1C 18888 bytes
SHA-256: 4d22ef938ae8c30742d7f196268af93067d45cbf0f8953a5d1bf763fdaf58a44
font_02_sfnt_off0001008e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1008E 11352 bytes
SHA-256: 4819d0025013b36c24e23781dc7e1f6aa9174c05de83310d9fcc0d8d537310f2