Malicious PDF — malware analysis report

Static analysis result for SHA-256 93eb57b18ce90298…

MALICIOUS

PDF

82.6 KB Created: 2021-09-15 15:01:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4d68e337992407dacc278909688b47b4 SHA-1: 90bce1118bb42a91bcc9a0cd71be19da30746c5e SHA-256: 93eb57b18ce90298e9747130f05e30dc8dacd8e1e4bf122314d380df8aa9e360
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it contains embedded JavaScript and a link farm pointing to compromised CMS uploads and disposable hosting. The embedded JavaScript likely facilitates the redirection to external URLs, which are numerous and varied, suggesting an attempt to distribute further malicious content or conduct phishing. The presence of multiple external links and the ML classification strongly indicate a malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://catamma.ru/uplcv?utm_term=chrome+on+mobile
    • https://mancomunidadvaldizarbe.com/userfiles/files/gepozab.pdf
    • http://nsmpublicschool.org/slbdavbatala/userfiles/file/nedufipume.pdf
    • http://air-ned.com/uploads/files/13067678014.pdf
    • https://copperscraphandlers.com/ckfinder/userfiles/files/gokeketeze.pdf
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161409bb504bb0---pimaxexupigedofojedutaku.pdf
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135aad28b490---52166379920.pdf
    • http://karate-talence.com/newsite/userfiles/files/nomekelejazodonawaro.pdf
    • http://ferien-in-zahren.de/images/file/99050666750.pdf
    • https://ags-car.com/upload/files/repufogutu.pdf
    • http://trunglamdecor.com/uploads/userfiles/file/rerivaweritakiwewukomu.pdf
    • http://yogaschoolofkerala.com/photos/editor/files/nukuvaz.pdf
    • https://kaisar168.com/contents/files/mojipibolojel.pdf
    • http://topoint.cc/userfiles/fckFile/20210904215736.pdf
    • http://abwingssuffolk2.com/uploads/files/dotapetutepidugozifuza.pdf
    • https://www.studioline.ie/ckfinder/userfiles/files/kopunaruvosuwetatasijo.pdf
    • http://ourgans.org/userfiles/files/91669568650.pdf
    • https://peiitw.com/Upload/ckeditor/files/8856932111.pdf
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613feaccbef52---sudabogupiwo.pdf
    • http://banner-ever.com/ckImg/files/79867539977.pdf
    • http://nabisori.com/userfiles/file/21049302545.pdf
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140219ec9ee0---tonojajafubep.pdf
    • http://heaig.org/editor/ckfinder/userfiles/files/fitawa.pdf
    • http://maximaviajes.com/FCKfiles/file/fikasekave.pdf
    • http://grandrosso.com/js/upload/files/40220126798.pdf
    • http://brandorbit.in/userfiles/file/95334919111.pdf
    • http://chothuexehochiminh.com/userfiles/file/lomemaxu.pdf
    • https://angem.fr/userfiles/file/zarafotafotupikoguzegenip.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_off0000dff8.bin
c0aa3f474c14c694269bc83a41c71274acb409bc2fad6650e454ebf92dad0661
pdf-font-stream PDF embedded font (sfnt) at offset 0xDFF8 17692 bytes
font_01_sfnt_off00010e3e.bin
11d82f3bccbf05accc4aff7dbc0bf205a857a8c3cc7b5926aca6090d630a3c6c
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E3E 10116 bytes
font_02_sfnt_off00012487.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12487 16792 bytes