Malicious PDF — malware analysis report

Static analysis result for SHA-256 981352c477b7236d…

MALICIOUS

PDF

82.4 KB Created: 2021-09-20 13:22:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a48d51321b42d6a8022110c0a54a8afe SHA-1: 86e9a8b33744181795cd3134caf93c09fdd69767 SHA-256: 981352c477b7236d05bd1655e16da6bdd10d6e875639f687912c68fca2f6f94e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file containing embedded JavaScript and a large number of external links, many of which point to compromised WordPress sites or disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is a common technique for executing malicious code within PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • 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://chcial.ru/uplcv?utm_term=works+gaming+injector
    • http://gemcom.org/userfiles/file/niguxaxinoworafemimu.pdf
    • https://lifo-sea.com/ckfinder/userfiles/files/39521574478.pdf
    • http://imosa.asia/uploads/files/202109131058192244.pdf
    • http://expertcomptablecourreges.fr/michel_courreges/userfiles/file/24297873305.pdf
    • http://aptekarynek.pl/zdjecia/fck/file/sejovidapi.pdf
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613db36a61491---gamojelusuwaxi.pdf
    • http://mmckno2010.zkosuchdol.info/files/55218292421.pdf
    • http://technoauto.jp/js/upload/files/73622161138.pdf
    • http://plise.org/userfiles/file/70336872375.pdf
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f22bb43be6---kasufavu.pdf
    • https://arhstroi.by/uploads/files/23771264145.pdf
    • http://korealabels.com/ckfinder/userfiles/files/bigivibikofo.pdf
    • https://cupanghitam.com/contents/files/rorakureromaz.pdf
    • http://shop-cartuning.pl/userfiles/file/migelojodulozur.pdf
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161327d484d160---18389998752.pdf
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/d854e9cb7abbb7feaaf6ee1d250f0e3a/wotumasapisilubapif.pdf
    • https://esvigo.com/upload/files/ropuzipevu.pdf
    • https://webmenuplus.com/images/file/dajaninekomo.pdf
    • https://stallion-international.com/userfiles/file/38850926750.pdf
    • http://schokofontaene.de/idata/64735090323.pdf
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/e8d283f4fd3c8e007981f89fa82709d0/wivuwunix.pdf
    • http://podarox.ru/public/files/femamej.pdf
    • https://yapluka-services.fr/userfiles/file/gidowisudibimas.pdf
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d89ad9225d---38281087829.pdf
    • http://unixsensor.com/uploads/files/202109080237506346.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_off0000de8a.bin
0054fc8c58ac371650a8ec2698d57df7a90ce5860c004c37dc86dde0a48b2a4a
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE8A 17328 bytes
font_01_sfnt_off00010b98.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B98 16792 bytes
font_02_sfnt_off000123af.bin
6130046c287b91201983f5aa2a19bdf16103b693d41e6861d91c7839ea78f576
pdf-font-stream PDF embedded font (sfnt) at offset 0x123AF 10744 bytes