Malicious PDF — malware analysis report

Static analysis result for SHA-256 e1e3af5e22864b1c…

MALICIOUS

PDF

96.5 KB Created: 2021-09-16 19:27:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 1abc08bfbb6aa38f60b4ec7a685f9409 SHA-1: efcbf74187b4a2ac721431770082cbe7070a65d1 SHA-256: e1e3af5e22864b1c31dc7a0979115598611453cf089569f34ff2bb56b23c459c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many external URIs pointing to potentially compromised or disposable hosting. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure and heuristic firings suggest a malicious intent to redirect users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://alstar.uz/images/shared/file/82358623303.pdf In PDF document text
    • http://cnpair.com/userfiles/file/rezipi.pdfIn PDF document text
    • http://studioindelicato.com/userfiles/files/labaxaxidoduzizevagusu.pdfIn PDF document text
    • https://lenaoyunlar.net/calisma2/files/uploads/tusevozitemoxukagosu.pdfIn PDF document text
    • http://koreaseals.com/ckfinder/userfiles/files/383827395.pdfIn PDF document text
    • http://mindennapi.hu/upload/file/92029650096.pdfIn PDF document text
    • https://toananhmedical.com/uploads/files/18699593532.pdfIn PDF document text
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/10dd9720ede1b587a0cc7faed9531a3c/wuzogudekobivonizimuterid.pdfIn PDF document text
    • http://efuturesthai.com/uploads/files/zenojifipuvu.pdfIn PDF document text
    • https://premiersuli.hu/files/files/suziwolomurufijisi.pdfIn PDF document text
    • http://aircond.md/upload_fck/file/32857494091.pdfIn PDF document text
    • https://sindonis.com/userfiles/file/danudufuwugaxunav.pdfIn PDF document text
    • http://tomgiongvip.com/uploads/files/file/zorobowovunipasojapatuv.pdfIn PDF document text
    • https://hram-uspeniya.ru/ckfinder/userfiles/files/sumin.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161416f9a13b0f---panuxitugako.pdfIn PDF document text
    • http://alles-vom-schreiner.de/userfiles/file/33470666991.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a7306564f2---xurabo.pdfIn PDF document text
    • https://proxus.nl/file/safijiwixerasabunobul.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=how+many+metalloids+are+in+periodic+tablePDF 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_off00011342.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11342 18384 bytes
SHA-256: 574d36b43d8b2d6eae30e4ec749e83e0f799fd7d66b13cdcffbb72c892f8a331
font_01_sfnt_off00014327.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14327 11004 bytes
SHA-256: 58ddf3e644982b6ca0fe13fdadaee306ef11f8314dca2f571f98d33d7df12871
font_02_sfnt_off00015c81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15C81 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1