Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef440ff33b8c0219…

MALICIOUS

PDF

96.0 KB Created: 2021-09-18 23:00:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 180c3f4428b6e3662742857b8a146763 SHA-1: 8bb4ddaeaf3a11c21e43fcaa1b805cff7244ea83 SHA-256: ef440ff33b8c0219146d7b4583ca857eba102d1d6dbf175f15ac589ede84f032
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by multiple heuristics and an ML classifier, specifically flagged as a phishing trojan. It contains numerous embedded URLs, many pointing to suspicious PDF files on various domains, suggesting a link farm or redirection mechanism. While no scripts were explicitly extracted, the PDF format itself can embed JavaScript, and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for linked content, common in phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/romitirapixudafux.pdf In PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/16138d813d210d---5747771699.pdfIn PDF document text
    • http://batterseataxi.com/survey/userfiles/files/7751001750.pdfIn PDF document text
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/6505290315.pdfIn PDF document text
    • https://beauti-full.ru/uploads/files/zofekowa.pdfIn PDF document text
    • https://agronlogistics.com/userfiles/files/59132807512.pdfIn PDF document text
    • http://studioambienteterritorio.it/userfiles/files/54127149529.pdfIn PDF document text
    • https://thaiahpa.com/flash/files/23127306011.pdfIn PDF document text
    • http://dvg.asia/ckfinder/uploadfiles/files/nidureraworuzuxuwanej.pdfIn PDF document text
    • http://digjamaica.com/app/webroot/files/53372931407.pdfIn PDF document text
    • http://nhatminhtrading.vn/app/webroot/uploads/files/luruxesibapivak.pdfIn PDF document text
    • http://ahzycw.com/upload_fck/file/2021-9-7/20210907005204500031.pdfIn PDF document text
    • http://urparitet.ru/admin/ckfinder/userfiles/files/60033383360.pdfIn PDF document text
    • http://technology-mp.it/userfiles/files/liwogu.pdfIn PDF document text
    • http://simsvizag.com/contentimages/file/93340461004.pdfIn PDF document text
    • http://cc-loges.com/uploads/file/8246118041.pdfIn PDF document text
    • http://ambvetfanini.eu/userfiles/files/berejoniginovuxidiki.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613a790354244---43258911107.pdfIn PDF document text
    • http://khyljg.com/uploadfiles/files/77269638771.pdfIn PDF document text
    • http://ruihuitax.com/files/file/muwutumufepiv.pdfIn PDF document text
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/75120575135.pdfIn PDF document text
    • http://2990592.ru/ckfinder/userfiles/files/govilaza.pdfIn PDF document text
    • http://uekekb.ru/!upload/files/zidisuxefepajo.pdfIn PDF document text
    • http://dieutrimun.myphamkangnam.vn/webroot/img/files/lukenokanozepubuzu.pdfIn PDF document text
    • http://alisawedding.com/upload/users/files/2393499978.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=swami+tapasyananda+bhagavad+gita+pdfPDF 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_off000111d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111D1 18420 bytes
SHA-256: 21de78de01c54da04d60b9f61e40ccedc0968343fa4162ff03311ccaa36f2537
font_01_sfnt_off000140d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140D5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000158ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x158EC 11028 bytes
SHA-256: 47e78bf713c7fd0e945bf578a0d4ded269e4af1380b47acf7273c31ff27375aa