Malicious PDF — malware analysis report

Static analysis result for SHA-256 374ae435f3131af6…

MALICIOUS

PDF

77.5 KB Created: 2021-09-23 22:04:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5c6575a4d97e3e9882cf2fa23d9c0826 SHA-1: e68fecca53a58769793ce48f99a9a9337b0bebbe SHA-256: 374ae435f3131af6d9fc3d5e70ac2335581d9d2a7c345f6545700b440890fbd7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document was flagged by ML classifiers and ClamAV as malicious, with multiple heuristics indicating it functions as a link farm. Numerous external URLs are embedded within the document, suggesting a phishing or malware distribution attempt. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic and the sheer volume of distinct hosts point towards a coordinated effort to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 5

  • 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.
  • 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://infrive.ru/uplcv?utm_term=ensemble+stars+apk PDF link annotation
    • https://g55net.com/webpagebuilder/ckfinder/userfiles/files/78479739629.pdfIn PDF document text
    • https://winstar-tools.com/UserFiles/editor/file/ratugotomu.pdfIn PDF document text
    • http://talk200.com/admin/admin/uploadfiles/file/vemavavewumev.pdfIn PDF document text
    • http://wsm.hk/images/files/wuwurojolowabisukoxasa.pdfIn PDF document text
    • http://customize.fr/fckeditor/editor/filemanager/connectors/php/img/Editor/file/14253568671.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/1614787cb49099---79932404570.pdfIn PDF document text
    • https://safe-international.com/userfiles/file/fowijirerosedimij.pdfIn PDF document text
    • https://dudikom.pl/userfiles/file/bawuwowevodetixof.pdfIn PDF document text
    • https://diamond-marketing.cz/soubory/92180829395.pdfIn PDF document text
    • http://nwatchonline.org/userfiles/file/9721744687.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149be26ef049---29776029851.pdfIn PDF document text
    • https://2-view.org/home/view/public_html/ckfinder/userfiles/files/pukamigit.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/riziliwikowexolujavifemo.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/10403471231.pdfIn PDF document text
    • https://rcvizovice.cz/ckfinder/userfiles/files/77665893983.pdfIn PDF document text
    • http://microsolder.hu/userfiles/files/75613425896.pdfIn PDF document text
    • https://tonere.shop/app/webroot/files/userfiles/files/kegunegib.pdfIn PDF document text
    • http://www.trisad.kz/ckfinder/userfiles/files/jifugifofizenur.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210908091521.pdfIn PDF document text
    • http://biancoacolori.it/userfiles/files/98702017022.pdfIn PDF document text
    • https://pcetravel.com/files/file/18600961802.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/xokabelamexorolosibutul.pdfIn PDF document text
    • https://getadoc.in/ckfinder/userfiles/files/36337753623.pdfIn PDF document text
    • https://shian-jin.com/UserFiles/files/98696426754.pdfIn PDF document text
    • http://pamatudarbai.lt/ckfinder/userfiles/files/53216287205.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16143a2800be00---radakedewuwolo.pdfIn PDF document text
    • 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_off0000c990.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC990 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e1a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1A2 18184 bytes
SHA-256: aab41a036829d1f86bb2b41a7b32276aa334cb02a850b9056af48881f1bb1f37
font_02_sfnt_off00011100.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11100 10416 bytes
SHA-256: aa2bccd29d7c11e16106b8cbc8cf23851eaed823c0a5a60c34a5c75e298df0d1