Malicious PDF — malware analysis report

Static analysis result for SHA-256 d58c40e9052042b8…

MALICIOUS

PDF

71.7 KB Created: 2021-09-26 09:55:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a72e0f9dc57f50ccc6c962939de62291 SHA-1: d2377c33e69d849a27f4737493eea7bd246780e0 SHA-256: d58c40e9052042b8b13ca382e16524f6fa590b4cd6567bcb8c1af5ceaf8fa180
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The sample was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates the document is a link farm on disposable hosting, with numerous distinct hosts and UTM term redirectors, suggesting a phishing or malware distribution scheme. The embedded URLs, such as http://netcentricnj.com/ckfinder/userfiles/files/xomudeno.pdf, are likely used to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://netcentricnj.com/ckfinder/userfiles/files/xomudeno.pdf In PDF document text
    • https://hurghadalife.net/userfiles/files/jarokejiveredunikir.pdfIn PDF document text
    • https://chorland-dining.com/webroot/editor-uploads/files/nukebemapejekebipijosijiv.pdfIn PDF document text
    • http://av-jet.ru/userfiles/file/peledov.pdfIn PDF document text
    • https://fereshtegan.net/basefile/fereshtegannet/files/39978466558.pdfIn PDF document text
    • https://www.seblocation.com/ckfinder/userfiles/files/wuvoxaravewagu.pdfIn PDF document text
    • https://tennis94.fr/img/pics/files/kuzusijemebakifuliv.pdfIn PDF document text
    • http://refah4ter.info/basefile/hotelrefah4terir/files/vovevawepog.pdfIn PDF document text
    • https://leise.ru/admin/ckfinder/userfiles/files/86151377047.pdfIn PDF document text
    • https://tiguan-wiki.ru/file/80416132123.pdfIn PDF document text
    • http://agavietnam.com/img/files/kemezisosexafavuk.pdfIn PDF document text
    • http://bulk-supplies.com/userfiles/files/zijagemegedas.pdfIn PDF document text
    • http://vizugy.hu/uploads/files/17552947760.pdfIn PDF document text
    • http://esistore.de/userfiles/file/19850417714.pdfIn PDF document text
    • https://securitydm.net/slicice/file/4199884799.pdfIn PDF document text
    • http://cesishotel.lv/res/wysiwyg/file/fogotedevamutu.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/962d30bda13100d92b815f77bc0fd6cb/91405055582.pdfIn PDF document text
    • https://atlanticcompact.org/userfiles/files/nijusodixasaz.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613ef84dc9f42---lomirejunima.pdfIn PDF document text
    • http://gowowdeli.com/uploads/files/94386718467.pdfIn PDF document text
    • http://bobmeetin.com/media/galleries/files/gugavadarivu.pdfIn PDF document text
    • http://nazycakes.com/userfiles/file/jejilipixidawi.pdfIn PDF document text
    • http://asfalon.com/__files/file/temetuzixesukefeki.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=android+navionics+freePDF 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_off0000b45a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB45A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC6C 17640 bytes
SHA-256: 353b96ea41e4329df0bb21e4c53a258d560c17a2cee41ada48c6101572a489b4
font_02_sfnt_off0000f9dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9DC 10372 bytes
SHA-256: 4c4b7af0e57d2dbd560df94f3e7e18fcb12a8028e57273040627590c45b12399