Malicious PDF — malware analysis report

Static analysis result for SHA-256 21ddf516f6486c10…

MALICIOUS

PDF

75.3 KB Created: 2021-09-18 05:00:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 358d170049b631b7026944403b8489a6 SHA-1: 4347230869b8525a87dbd5a5fa3b471a09882587 SHA-256: 21ddf516f6486c10b5ba986bfd7d8e9f050485242becf9f97f55d7be8df415b7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URLs, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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 https://cructi.ru/uplcv?utm_term=function+of+stomach+in+the+digestive+system PDF link annotation
    • https://hanomanberjaya.com/contents/files/bobakokisubuligewel.pdfIn PDF document text
    • http://combatkuntao.com/ckeditor/ckfinder/userfiles/files/zesifawibamawi.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file///51448538517.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/xezuxomazagezinabino.pdfIn PDF document text
    • http://tongshengchem.com/ckfinder/userfiles/files/67251295396.pdfIn PDF document text
    • http://kagoshimakojintaxi.com/userfiles/file/pudofimubosu.pdfIn PDF document text
    • https://autotronics.vn/userfiles/file/88943245656.pdfIn PDF document text
    • http://lianbang123.com/uploads/files/202109010635266717.pdfIn PDF document text
    • http://veganogle.es/uploads/ckfinder/files/52681468662.pdfIn PDF document text
    • http://sonhanint.com/uploadpic/sun/files/202109101951138539.pdfIn PDF document text
    • https://goldenlinejsc.com/userfiles/file/39787018908.pdfIn PDF document text
    • https://conexusinternational.com/ckfinder/userfiles/file/zobowilulagasuwij.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e94619207a---jizulituzilepav.pdfIn PDF document text
    • http://digitalpolicycouncil.org/imagenes/file/pubumusepova.pdfIn PDF document text
    • https://kibledergisi.net/resimler/files/raxanopapuridividodeguj.pdfIn PDF document text
    • https://hr-serdahel.hu/images/file/revigabidiselufuvagorok.pdfIn PDF document text
    • http://generaldistco.com/images/file/38707002095.pdfIn PDF document text
    • http://nt-module.ru/ckfinder/userfiles/files/18031652351.pdfIn PDF document text
    • https://wfca-czech.cz/temp/userfiles/files/mamunujazigeji.pdfIn PDF document text
    • http://kingswaytyres.com/project/kingsway/uploads/file/5711757367.pdfIn PDF document text
    • http://studiopol.it/userfiles/files/famibune.pdfIn PDF document text
    • http://mikllc.mn/uploads/files/xukamesepotitolibur.pdfIn PDF document text
    • https://www.champagne-auge-dascier.com/ckfinder/userfiles/files/60582705701.pdfIn PDF document text
    • https://bloomlight.pl/_bloom/file/norixire.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613f81b92dbc3---zekilowasiguninab.pdfIn PDF document text
    • http://mutitar.com/user_img/files/64548402177.pdfIn PDF document text
    • 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_off0000c2e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2E7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000daf9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAF9 16584 bytes
SHA-256: 0401b2a8fbda30096b158c342ecd6cc13f9ddfd067f36c21fc7d8b8174527984
font_02_sfnt_off000105ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105AB 11032 bytes
SHA-256: af43c4318296204be8dd9ced617556d7d54c0a4cce508bf49708ddc73925a6e7