Malicious PDF — malware analysis report

Static analysis result for SHA-256 4822f21cf8b73895…

MALICIOUS

PDF

79.1 KB Created: 2021-09-13 15:10:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1c9e255cd9e22f4dfbeff3223302fc03 SHA-1: 1cc822467cac826dfd2a6134b62f95153f0536f2 SHA-256: 4822f21cf8b73895353b3588b6ec97d94cd601dea4871ba649a90766996b1470
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external links, many pointing to PDF files hosted on various domains. This structure is indicative of a link farm designed to distribute malicious content or phish users. The presence of ClamAV detection and ML classifier flagging further supports its malicious nature. The embedded JavaScript likely facilitates the redirection or download process.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://cdkkck.com/uploadfile/file/20210906052558.pdf In PDF document text
    • http://grafichesirio.com/userfiles/files/mazofovomaka.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/46270161061.pdfIn PDF document text
    • http://world-housing.jp/ckfinder/userfiles/files/gumixejawewopo.pdfIn PDF document text
    • http://peaceinsrilanka.lk/userfiles/file/foxusozeline.pdfIn PDF document text
    • http://bekkercoon.ru/ckfinder/userfiles/files/bebanokuvonafujawunul.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16138a38e04102---binelatuxeviviwuxiw.pdfIn PDF document text
    • http://zoop-tech.com/ckfinder/userfiles/files/fomibubuperavuxologesuwo.pdfIn PDF document text
    • http://traiteur-ribot.fr/userfiles/file/30966041087.pdfIn PDF document text
    • https://www.gurgy.net/ckfinder/userfiles/files/73638706085.pdfIn PDF document text
    • https://gosselindesign.com/images/from_fckeditor/fichiers/22033763377.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/7djjq2f64jhtc9fgb1b37q34b1/tuzudejiju.pdfIn PDF document text
    • http://retco.ge/ckfinder/userfiles/files/rowobifezed.pdfIn PDF document text
    • http://asvpp.fr/pdf/75232685110.pdfIn PDF document text
    • http://zs-g.jp/app/webroot/js/ckfinder/userfiles/files/86287300825.pdfIn PDF document text
    • http://bonsite.nl/phpcmsys/file/zewibixemoxakebijevud.pdfIn PDF document text
    • http://nena-artspace.com/ckfinder/userfiles/files/92007149788.pdfIn PDF document text
    • https://hram-uspeniya.ru/ckfinder/userfiles/files/45034756720.pdfIn PDF document text
    • http://adbuilder.at/ckfinder/userfiles/files/rireruxazimefad.pdfIn PDF document text
    • http://wingmanresearch.com/userfiles/files/porosumiwedelilobepa.pdfIn PDF document text
    • http://trips-in.com/ckupload/files/bakifaz.pdfIn PDF document text
    • http://laiyi-art.com/userfiles/file/retobeburivu.pdfIn PDF document text
    • https://htchninc.com/d/files/lajedesipemibe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=watch+mulan+2020+online+free+123PDF 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_off0000cde9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDE9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e5fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5FB 18136 bytes
SHA-256: fcd69cb21818752ab4c2b83b4f637a4fc948329346649dfea7ada5ac86234618
font_02_sfnt_off00011554.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11554 10992 bytes
SHA-256: 95220a7b629a6412cc54dac311dfc32b823ec98c88bb91dce7d751256122e244