Malicious PDF — malware analysis report

Static analysis result for SHA-256 9521a7ac8b61181a…

MALICIOUS

PDF

73.2 KB Created: 2021-09-30 20:48:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8090b02afc63ed2b0e5ed2ea73c6fcb9 SHA-1: e53bc5f07ab3518c73eae4ce3cf7b3f28c81410d SHA-256: 9521a7ac8b61181ac90d514f8718e2c2b1b2fd71574989ddd1ad8a4c339c8f11
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document contains a link farm pointing to numerous external URLs, many hosted on compromised CMS uploads or disposable domains, suggesting an attempt to distribute malicious content or conduct phishing. Embedded JavaScript was also detected, which could be used to further obfuscate the malicious activity or redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9827

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • 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 https://queure.ru/uplcv?utm_term=3+multiplayer+games
    • https://intrigantka.ru/images/userfiles/file/sifalatetidawerorufapitud.pdf
    • http://kinel-hunter.ru/upfiles/file/99958510466.pdf
    • https://academiapreprod.riportico.com/userfiles/files/vulatokabisosojujoliz.pdf
    • http://sensitiva.fi/UserFiles/File/sonigidi.pdf
    • https://gmt-tw.com/app/webroot/userfiles/files/95567421678.pdf
    • https://censcakmu.org/board/file/files/47259361620.pdf
    • https://jmcoverseaspvtltd.com/uploads/files/xotudefazirovisigap.pdf
    • http://poketomecam.com/uploads/files/6658038133.pdf
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/161451e0c3f69c---9885877185.pdf
    • https://jobtiara.com/files/files/junowuzaf.pdf
    • http://garageanything.com/js/upload/files/4432098496.pdf
    • https://vico-real-estate.com/ckfinder/userfiles/files/ruzije.pdf
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1615278cfd17a0---jiduk.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ce442c3295---89333912788.pdf
    • https://erdemlerkoleji.com/resimler/files/vaxadufotiwetuja.pdf
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/40140434929.pdf
    • http://xn----7sbqwxdbhblh2h.xn--p1ai/data/file/retime.pdf
    • http://sugarfree-gelato.com/upload/file/36515859409.pdf
    • https://landbar.com/app/webroot/js/ckfinder/core/connector/upload/files/52479076566.pdf
    • https://newsru.md/upload/userfiles/files/65459000548.pdf
    • http://pactolous.hu/upload/file/femaziwepakunewerelu.pdf
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16150c41dc45ab---gozanelikivukifugokopek.pdf
    • http://palami.by/images/file/fojovew.pdf
    • http://wangnatheater.bpi.ac.th/ckfinder/userfiles/files/47516851691.pdf
    • http://beergolfers.com/blog/images/file/90411358247.pdf
    • http://byecook.com/ckupload/files/pilaje.pdf
    • http://forumts.com/ckfinder/userfiles/files/40105705756.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b828.bin
b68ee5b397b6e305f0100b62b6dde34660273015c8b6d3b0951630d3b7030a8d
pdf-font-stream PDF embedded font (sfnt) at offset 0xB828 10660 bytes
font_01_sfnt_off0000d091.bin
d627a5ed52d2179bae19406f208522ab5116f08968995447e767b779936fc1e6
pdf-font-stream PDF embedded font (sfnt) at offset 0xD091 18160 bytes
font_02_sfnt_off0000ff7a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF7A 16792 bytes