Malicious PDF — malware analysis report

Static analysis result for SHA-256 163e1a73d5562b8d…

MALICIOUS

PDF

74.8 KB Created: 2021-09-27 22:09:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: f207c93511e0e622139e0f23b853d1a2 SHA-1: 2c3fb14d2e665c9bb977f847a8d76979f3e201bb SHA-256: 163e1a73d5562b8dd42c5efc46d68159696f8b57182db75e07414343f5915e81
126 Risk Score

Malware Insights

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

The sample was identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm on disposable hosting. The embedded URLs, such as https://infrive.ru/uplcv?utm_term=prevent+screen+from+locking+android, likely serve as lures for phishing or to distribute further malware. Although no scripts were explicitly extracted, the PDF structure and the nature of the heuristics suggest an attempt to exploit users through malicious links, aligning with spearphishing attachment tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9907

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=prevent+screen+from+locking+android PDF link annotation
    • http://schubert-hh.de/image/file/44280636766.pdfIn PDF document text
    • http://chipublichouse.com/ckfinder/userfiles/files/16227788714.pdfIn PDF document text
    • http://kabaretyimpresariat.pl/Upload/file/63680287105.pdfIn PDF document text
    • http://ural-resyrs.ru/data/file/88807633485.pdfIn PDF document text
    • http://jj-metals.com/userfiles/file/2021092513464273499.pdfIn PDF document text
    • http://basumati.com/app/webroot/ckfinder/userfiles/files/7659780903.pdfIn PDF document text
    • https://laundrybyconrads.com/nbloom/fckuploads/file/supanajijuzexadif.pdfIn PDF document text
    • https://liftsystems.ro/LiftFiles/file/9485944055.pdfIn PDF document text
    • https://360clothing.indicsys.com/home/www360cl/public_html/uploads/images/files/70943663103.pdfIn PDF document text
    • http://baraanduliaptti.org/userfiles/file/pavux.pdfIn PDF document text
    • https://klcconsulting.eu/klc/file/50823422041.pdfIn PDF document text
    • http://shippingengineering.com/files/ckeditorothers/41914915741.pdfIn PDF document text
    • http://embody.box8websites.com/ckfinder/userfiles/files/gesifib.pdfIn PDF document text
    • http://unitekinfostructures.com/userfiles/file/25857546862.pdfIn PDF document text
    • http://vanillasky-ch.com/images/files/pezubosini.pdfIn PDF document text
    • https://athenaeumchessclub.com/ckfinder/userfiles/files/jesujaxanumosokuwugawulu.pdfIn PDF document text
    • http://gartenstadt-apotheke.com/userfiles/file/levojugonipunodumidalev.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/46450076957.pdfIn PDF document text
    • http://www.parinet.fi/tiedostot/files/rawudona.pdfIn PDF document text
    • http://labradory.pl/file/jisexolunumafoku.pdfIn PDF document text
    • http://clubselectionvoyages.com/images/file/44152774965.pdfIn PDF document text
    • https://patidarpalanpur.com/web/k/main_admin/ckfinder/userfiles/files/84255042444.pdfIn PDF document text
    • http://prtourusa.com/FileData/ckfinder/files/20210902_9A194901B924E69A.pdfIn PDF document text
    • http://elcwma.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/40599741509.pdfIn PDF document text
    • http://flixgolf.com/ckeditor/ckfinder/userfiles/files/64813451312.pdfIn PDF document text
    • https://olboihorgaszto.hu/editor_up2/78334582200.pdfIn PDF document text
    • http://infinity-pro.ru/userfiles/file/76686550532.pdfIn PDF document text
    • http://01host.ru/userfiles/files/nabotezuwuvapojex.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_off0000bb45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB45 18732 bytes
SHA-256: c1212a042c187f61f861448c37865ee65f8aebd9bd53cf829e7f73ebb40d0589
font_01_sfnt_off0000eb97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB97 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000103ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103AE 10976 bytes
SHA-256: ffde9103d776214a79ff270d3125e289dc890548dae469686206daec3b600d10