Malicious PDF — malware analysis report

Static analysis result for SHA-256 f88551551ae095e3…

MALICIOUS

PDF

83.0 KB Created: 2021-09-14 20:07:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6a9599269244828b0881a911290556f0 SHA-1: 7d2eb32337c0d52f54e0db2d951bb2bd6f320fd3 SHA-256: f88551551ae095e325fad4fd97a0572da6c790ba265ac274de1c5bcba4aa9306
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, with high-severity heuristics indicating a browser extension installation lure. This suggests a social-engineering attack aimed at tricking the user into downloading and executing further malicious content. The embedded URLs, while many are benign, point to a link farm strategy, and the overall structure is consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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 http://swiss-ex.com/images/blog/file/10466980286.pdf In PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-4/20210904173551161397.pdfIn PDF document text
    • http://www.specemc.ru/upload/files/74071436296.pdfIn PDF document text
    • https://k31szmq42-nu28.com/contents/files/mupeturilumekan.pdfIn PDF document text
    • http://suphammamnon.org/uploads/files/77386735874.pdfIn PDF document text
    • http://sevgineslianaokulu.com/ckfinder/core/connector/php/uploads/files/lamorosutukosawuwetivopex.pdfIn PDF document text
    • http://oldadmin.k12cart.com/media/files/xogixilerewetujagabamasof.pdfIn PDF document text
    • http://fertilityupdates.com/userfiles/files/giwazutep.pdfIn PDF document text
    • https://camphacement.vn/upload/files/pawinuvuvibuwipajepodajis.pdfIn PDF document text
    • https://mosaicopeoplecorporation.com/ckfinder/userfiles/files/lopolozugokatik.pdfIn PDF document text
    • https://www.icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/32634951.pdfIn PDF document text
    • http://4darchitecture.org/img/all/naxezaxege.pdfIn PDF document text
    • http://vietsinphar.com/uploads/files/35540734566.pdfIn PDF document text
    • http://recit-de-vie.fr/userfiles/file/28560489881.pdfIn PDF document text
    • http://optykglowacki.pl/obrazki/files/26393332385.pdfIn PDF document text
    • https://dortmundpools.com/contents/files/tasesivozuxizavipekipe.pdfIn PDF document text
    • https://taucaotoccatba.vn/images/news/files/40848328547.pdfIn PDF document text
    • http://uptownherndon.com/uploads/files/28061031904.pdfIn PDF document text
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/912afac846e2780b347e3383aa61ace2/godaso.pdfIn PDF document text
    • https://holycrosshealthcare.com/userfiles/files/44168794756.pdfIn PDF document text
    • http://giustizianuova.it/userfiles/file/76522631365.pdfIn PDF document text
    • http://cityfate.com/files/files/9913558212.pdfIn PDF document text
    • http://naturpix.ch/cmsimages/file/wekutimurazonan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=how+do+i+hide+the+navigation+barPDF link annotation
    • 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_off0000dc36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC36 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f448.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF448 19528 bytes
SHA-256: e297f776b8d24c1aea24135fdd1cf1c284effeca7dfcf0ff1db0df98e35b830a
font_02_sfnt_off000126a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126A4 10596 bytes
SHA-256: 31beab2fd11f99515ac3f2f473fa0f167711c2da2e1d0db86a3d9bdc37d2b3f2