Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4cb9ffc089bdda1…

MALICIOUS

PDF

70.0 KB Created: 2021-09-24 21:52:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 8f94583bdc74fc596aeeba62a438b5d1 SHA-1: f074ea0dea923d8232d3908a1806202352aa8fc3 SHA-256: a4cb9ffc089bdda17a1b5abdc9f0867fe525c37636a4da50df9ea33324dbd608
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the document functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS platforms. The presence of numerous unknown URLs suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://mariapolis.es/ckfinder/userfiles/files/18770694013.pdf In PDF document text
    • http://chinasoftcore.com/userfiles/file///bitezalixuwodipamugumoma.pdfIn PDF document text
    • http://sarkar.ie/userfiles/file/47705962243.pdfIn PDF document text
    • http://ucinnovation.ru/admin/ckfinder/userfiles/files/97527212908.pdfIn PDF document text
    • https://questyme.com/userfiles/file/banosaz.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f3a3a9f6ba---28877936640.pdfIn PDF document text
    • http://alt-1c.ru/userfiles/file/49850646025.pdfIn PDF document text
    • https://shen-su.eu/gfx/userfiles/files/17257046322.pdfIn PDF document text
    • http://coumert.com/images/file/87770031404.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/n77daf4j3eg7fpmq860ruhcf6b/26529644545.pdfIn PDF document text
    • https://siltri.com/fck_upload/file/kuzorojisizufezad.pdfIn PDF document text
    • https://limsurempat.com/contents/files/sisefevodadijimopejasu.pdfIn PDF document text
    • http://scbczy.cn/up_files/file/20210922_091651.pdfIn PDF document text
    • http://naoshima-habitant.com/images/blog/file/lezonowududitofulu.pdfIn PDF document text
    • https://sona3elkhair.com/userfiles/file/53800164875.pdfIn PDF document text
    • https://gloriamus.org/Uploads/userfiles/files/87421214705.pdfIn PDF document text
    • http://ozkayalartrans.com/userfiles/file/74303373402.pdfIn PDF document text
    • http://nhatminhtrading.vn/app/webroot/uploads/files/76725632639.pdfIn PDF document text
    • https://slide-bearing.com/d/files/42726959274.pdfIn PDF document text
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/36b8b7695f21e740c79f6d6889f8d931/vozoliwuxevabufodozutaju.pdfIn PDF document text
    • http://launensia.cz/ckfinder/userfiles/files/11224475474.pdfIn PDF document text
    • http://www.gpkoaee.ru/ckfinder/userfiles/files/tovipuraxevofofes.pdfIn PDF document text
    • https://albawadiroad.com/userfiles/files/87927264925.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135490a876ec---26480756112.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/16140bc1954c6d---nagimewofopiwarexiluxikab.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=happy+wheels+sword+throwPDF 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_off0000b1a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1A2 10484 bytes
SHA-256: 594293d3c20cde9e0ac0d343db0a4ee4d73f554c27c64704cee51b3b419509a9
font_01_sfnt_off0000c9b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9B0 16288 bytes
SHA-256: dd59b2b17b05ccbf38c76947f5fa8cf8bed3ca97744614121a8184093489dfc6
font_02_sfnt_off0000f26e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF26E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1