Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4bbf2e29da33069…

MALICIOUS

PDF

111.2 KB Created: 2021-06-22 23:53:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 69c544d704e5bed51f8cf3ff41e17d3e SHA-1: 708d12a36382358944aa28ac321a78b5ee60088e SHA-256: d4bbf2e29da33069ff9634be4f013f106c83808dda8f33f9a45ebbac9203f4d0
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan and an ML classifier flagged it as malicious. Several heuristics indicate the PDF is a link farm, with many links pointing to compromised CMS uploads and disposable hosting. These links likely serve as lures for phishing or to distribute further malware. No scripts were extracted, and the document body was heavily obfuscated.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://contabil-fiscal.ro/mm/file/kupexejisifutaxuteg.pdf In PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/bbi2019tddudgo2dap241c6hqc/bunasugukepujudozop.pdfIn PDF document text
    • http://www.assignproject.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091cca1abd70---86663787630.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/290845542185.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/160813589e9777---92832618243.pdfIn PDF document text
    • https://fruzsiflame.hu/userfiles/file/futaj.pdfIn PDF document text
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/7d73de59205c08bafc111253c22d6b9a/vatonefepu.pdfIn PDF document text
    • https://getlovebooks.com/wp-content/plugins/super-forms/uploads/php/files/214cb05e914d1ae1ab94e655cc236051/41790169780.pdfIn PDF document text
    • https://www.americansummercamps.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ceca81600f---bixutoxifepuvo.pdfIn PDF document text
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/e77565e00b5be67e5d2ad5cde918c064/38822555257.pdfIn PDF document text
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082bdb490947---96351609594.pdfIn PDF document text
    • https://ancoraeducacion.com/images/78512919800.pdfIn PDF document text
    • http://stacjaregeneracja.pl/userfiles/file/86588317785.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=song+of+lawino+full+textPDF 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://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000154f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x154F2 4924 bytes
SHA-256: 35f1ca5b9d67ba34d5d9cd821de314d0c4237600a99499b08318a7a143bdca73
font_01_sfnt_off000165e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x165E2 3052 bytes
SHA-256: 84d1842ec43a456dc24d39caf0ddc38372e8b432d45c2545336560b57b08c413
font_02_sfnt_off000172a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x172A4 11260 bytes
SHA-256: 35d22712c0736483ec17bc406399f9e0ba427f06650d60d7def1c5ebb01e0d6b
font_03_sfnt_off00019952.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19952 16352 bytes
SHA-256: 67df87a40f8d4a63040cfe2508754e3f8575c2dda2d73323de624af28a489072