Malicious PDF — malware analysis report

Static analysis result for SHA-256 531cdc293cf43cfc…

MALICIOUS

PDF

84.4 KB Created: 2021-09-15 10:17:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b2b1f719ca3d3733611643ad2ea5b1dc SHA-1: 294b85c1dc1865f47cbef3d9467220a978011796 SHA-256: 531cdc293cf43cfc18be172ac519fe10b4349adfa3136043eb1efeaf4dd9b051
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. The heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to PDF files, likely serving as a lure for users seeking software activators. The presence of external URIs and the overall structure suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://ural-resyrs.ru/data/file/16000809686.pdf In PDF document text
    • http://daedukgs.com/admin/fckeditor/data/file/20210912040856.pdfIn PDF document text
    • http://iamsong.vn/uploads/files/97550603893.pdfIn PDF document text
    • http://amoy-art.com/Upload/file/dewozokov.pdfIn PDF document text
    • http://zopos.zohukum.com/ckfinder/userfiles/files/91917181820.pdfIn PDF document text
    • https://ctcitsupport.com/media/files/kujuzilabuzezi.pdfIn PDF document text
    • http://matonaklawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/89065455372.pdfIn PDF document text
    • http://grandp.ru/userfiles/file/kopovajivezerepolomexer.pdfIn PDF document text
    • https://cursosadistanciayonline.com/medios/files/logus.pdfIn PDF document text
    • http://chamdure.com/DATA/files/60424090317.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/2pt9k1ive5s3u1r6b51ijbm97o/samixib.pdfIn PDF document text
    • https://toyotaautobody.com/ckfinder/userfiles/files/83905852646.pdfIn PDF document text
    • http://taxfreepoint.com/file/54407666978.pdfIn PDF document text
    • http://www.saaegfpolis.org.br/ckfinder/userfiles/files/83763941467.pdfIn PDF document text
    • http://a-aqua.fr/ressource/site-image/files/lizadev.pdfIn PDF document text
    • https://perfecthospitals.com/ckfinder/userfiles/files/wivasumi.pdfIn PDF document text
    • http://interno-kazan.ru/upload/files/wowixatepizavuda.pdfIn PDF document text
    • http://ingegneriarossi.it/userfiles/files/xufopajagadeluwetuwapake.pdfIn PDF document text
    • https://mobile-translator.eu/app/webroot/media/files/fozebazezodaturejimeku.pdfIn PDF document text
    • http://zwickerfoto.hu/_user/file/nejakaliv.pdfIn PDF document text
    • https://998.geektic.com/geektic/files/telixe.pdfIn PDF document text
    • https://hippodrome-compiegne.fr/www/uploads/file/xonetadesavidegagevurog.pdfIn PDF document text
    • http://liga-stf.ru/i/upload/files/86875622239.pdfIn PDF document text
    • http://goodfortune.hk/UpLoadFile/file///34556120188.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f935eae3f0---pupokusosodo.pdfIn PDF document text
    • https://www.tunnel.de/files/uploaded/file/26906015383.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=windows+7+home+premium+64+bit+activatorPDF 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_off0000e237.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE237 11412 bytes
SHA-256: a894ed31f881fa48704d5adf27b0a04066594d5672b62c38b2b923c57f6f732f
font_01_sfnt_off0000fce2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCE2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000114f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114F4 17812 bytes
SHA-256: 1bd27ad226f08b369e5d5c91926eb2fadc9872231ab56840b69c209d1ca69f5f