Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5e4cf4dd81dbe12…

MALICIOUS

PDF

82.6 KB Created: 2021-09-19 11:32:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: d25f7d6ed3f3fbeb654cc44c3f2cdf89 SHA-1: 760f82f13bd3db4c4749fd452482791e35dfd21f SHA-256: a5e4cf4dd81dbe12ed45a5b7aa8b6300414058b9faadf07f3ef2d549214ab2a0
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, exhibiting characteristics of a link farm with numerous distinct hosts. The presence of multiple embedded URLs, many pointing to PDF files on disposable domains, strongly suggests a phishing or malware distribution attempt. The document body is heavily obfuscated and likely contains further malicious content or redirects.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://jjkxmy.com/upload/files/202109111619272278.pdf In PDF document text
    • https://tourpon.kr/FileData/ckfinder/files/20210905_F79283D0D7188342.pdfIn PDF document text
    • http://hanabi-la.com/uploads/files/44611462974.pdfIn PDF document text
    • https://mackbeks.com/files/file/96087364249.pdfIn PDF document text
    • http://stamforgtechnologies.com/uploads/17582271307.pdfIn PDF document text
    • https://www.aukuras.org/ckfinder/userfiles/files/vivezukiridefosunijemiko.pdfIn PDF document text
    • https://strategieb2b.com/userfiles/file/62254984513.pdfIn PDF document text
    • http://realcomfort.ru/content/upload/file/tarupawofazuzezexaluvari.pdfIn PDF document text
    • http://margheritango.it/userfiles/file/petok.pdfIn PDF document text
    • http://xn--lv0az70cxar.tw/uploads/files/202109040832552374.pdfIn PDF document text
    • http://uro-medical.pl/zdjecia/fotki/file/69172461313.pdfIn PDF document text
    • http://mebelhotel.ru/images/news/file/57447522183.pdfIn PDF document text
    • https://bonekarusa.com/contents/files/79070258083.pdfIn PDF document text
    • http://nage-z.com/ckfinder/userfiles/files/67192521817.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16146ee6f0a940---zefomojodil.pdfIn PDF document text
    • http://meubelenindex.nl/images/uploads/fuzeperaruxen.pdfIn PDF document text
    • http://abcbyspu.net/ckfinder/images_store/files/rovevugif.pdfIn PDF document text
    • https://swalaya.in/userfiles/file/33190947550.pdfIn PDF document text
    • http://baracenter.be/userfiles/file/mukavelowelinatozupeb.pdfIn PDF document text
    • https://olterus.org/contents/files/mawemipirud.pdfIn PDF document text
    • https://ensegun2.com/ckfinder/userfiles/files/gowuruzi.pdfIn PDF document text
    • http://qwerty.pl/_data/file/darezabunesa.pdfIn PDF document text
    • https://wodepcb.cn/uploadfiles/files/16964234048.pdfIn PDF document text
    • http://nowyhotelik.pl/userfiles/file/94918708001.pdfIn PDF document text
    • http://chamdure.com/DATA/files/5294271713.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=free+keyboard+app+for+android+phonePDF 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_off0000e1bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f9d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9D4 10608 bytes
SHA-256: e88b8205a2186a1df1eba312f96303b84f81acb160ee882ab7d7745695ade245
font_02_sfnt_off000111b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111B4 16524 bytes
SHA-256: 838516c71ffde96e558696bd5776306a7653873bd353ec5dd7e7a2ac1fa52170