Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c25bfc0a7f1b156…

MALICIOUS

PDF

87.2 KB Created: 2021-08-03 22:25:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f94de614f74464dcfd71c204b89cbc45 SHA-1: 1a2d3d67b892e06b60642b1db0a5497a19b2ec12 SHA-256: 4c25bfc0a7f1b156dbf2d353d77fda8dc0e14afa15a0247f17efab35d583f910
156 Risk Score

Malware Insights

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

The PDF document contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as link farms. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to lure users to phishing or malware distribution sites. The document body is heavily obfuscated and unreadable, suggesting it's not intended for direct user interaction but rather to host malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://ambientltg.com/wp-content/plugins/super-forms/uploads/php/files/e41233d2a195a2a62e15309717f663e7/zogufunibu.pdf In PDF document text
    • http://redeyeldn.com/userfiles/file/gixejoxifipepaluv.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/92l2ee9smhldd6n7fg0v6oajfr/78883194614.pdfIn PDF document text
    • http://staging.impactredevelopment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160775b8bdb643---lazalawanomekawiwekex.pdfIn PDF document text
    • https://www.beadvised.co.uk/wp-content/plugins/super-forms/uploads/php/files/e2ecb938529f6a8cc98c4f512a2e0a5a/23851563858.pdfIn PDF document text
    • http://sriagasthiyarastro.com/FCKeditor/userfiles/file/suvatefawalatozuxuzonepu.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1609b9f9538056---rugaloz.pdfIn PDF document text
    • https://empylean.com/wp-content/plugins/super-forms/uploads/php/files/5vj8qmjb1p3gsj2v0ed7jrku85/tibigerodonefegozumipedar.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160afe1ae62bc4---39463275718.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/54138239089.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e26e31bd068---3589338714.pdfIn PDF document text
    • https://mediaget.ru/userfiles/files/12168568688.pdfIn PDF document text
    • https://kemxoi.vn/app/webroot/files/images/pages/files/94892508690.pdfIn PDF document text
    • https://apparel.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/4d3bcf6cae3c4ea52b7a47d7c3cfcb42/55363393290.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/7c5ifkq92kr0j9euta79o01s1o/71012557280.pdfIn PDF document text
    • http://sammyuriasproperties.com/userfiles/files/77614985096.pdfIn PDF document text
    • http://septumdent.com/img/userfiles/files/43531605082.pdfIn PDF document text
    • https://angkortaxiservice.com/userfiles/file/6559434059.pdfIn PDF document text
    • http://fsanaq.com/upload/file/2107271609227872511s5gt3occv98.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/34274634476.pdfIn PDF document text
    • https://ourcampuswindow.com/ckfinder/userfiles/files/lerukulirap.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085da3abfd27---tevigasaguwil.pdfIn PDF document text
    • http://dongkoo.com/uploads/editor/files/90532821733.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=delta+airline+crew+uniformsPDF 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_off0000eef3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEF3 18052 bytes
SHA-256: c6c3995726befd202c6c1dc14e42137274582111aa32101c3b2a0a59ad250fc9
font_01_sfnt_off00011e8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E8A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000136a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136A1 10684 bytes
SHA-256: d152e9452ee163d6e2ffc2c94c236e16c770144e039ffee223ae1ddb19b84550