Malicious PDF — malware analysis report

Static analysis result for SHA-256 e3f7c5ccd17a8ca2…

MALICIOUS

PDF

70.1 KB Created: 2021-09-16 23:32:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0d78f5f22fff2c95c6f792aa85364cd6 SHA-1: 2db94ba4ff15b156f72a70689475904566a3298a SHA-256: e3f7c5ccd17a8ca2b1796b6c7ab338fdab473ce427cb30bd2c5dda7bdf4bd774
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious content. It also functions as a link farm, directing users to multiple compromised or disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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=can+you+transfer+sms+from+android+to+android
    • http://amandatour.ru/js/ckfinder/userfiles/files/7974466264.pdf
    • http://all-paca.com/ckeditor/ckfinder/core/connector/php/uploads/files/44234685230.pdf
    • http://3gr-group-com.gbintl.com/ci/userfiles/files/28539236744.pdf
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/4a5eb950d4e3c1aff605518280c8bd7d/xidugodivasira.pdf
    • http://cdwy028.com/uploadfile/file/20210911062446.pdf
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f8c53e7ae4---nurukometowajux.pdf
    • https://tmtteks.com/files/33252554028.pdf
    • https://alaqart.atelierleuthold.ch/userfiles/files/82480624969.pdf
    • http://davidhammerstein.org/ckfinder/userfiles/files/torokagoluzewirewub.pdf
    • http://xn--49s538bo8ux8c.net/userfiles/file/povojofuf.pdf
    • http://www.schule.havonix.com/ckfinder/userfiles/files/87130120139.pdf
    • http://guojingmall.com/userfiles/file///fepeveb.pdf
    • http://sinoscaform.com/upload/ckimg/files/202109022220042097.pdf
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/f2407a8f3845656cd7a2be54c2ff0ef9/59889668374.pdf
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613829b96e9f0---15068493335.pdf
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613352141092b---39945313414.pdf
    • http://obraz-tlt.ru/userfiles/file/tezumujisufadorutizakegum.pdf
    • http://rheumatology.institute/upload/content/file/39593488840.pdf
    • http://pokebarslo.com/uploads/files/19927193774.pdf
    • https://terrebleue.org/userfiles/file/2929884990.pdf
    • http://hondatayho.vn/images/ckeditor/files/87232697691.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_off0000b2e4.bin
5cb46c633e972268a757c09f1eb75724a5926d9c341a6ddd942205da0044a19d
pdf-font-stream PDF embedded font (sfnt) at offset 0xB2E4 10716 bytes
font_01_sfnt_off0000cb94.bin
f1394263f612caf95142a5c9596cb0d9c0f228345dc50653794f0a3fc797d134
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB94 15636 bytes
font_02_sfnt_off0000f328.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF328 16792 bytes