Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f335ed408381ee0…

MALICIOUS

PDF

79.9 KB Created: 2021-09-11 14:07:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b291dcad21d79391eb65bcda5aff41d5 SHA-1: df7a031cf79ed2eb62fffc92cd5a91b164bb0862 SHA-256: 3f335ed408381ee0db222c0ac35cabc7e784cdf171dfaa33cfe16e1b88586d06
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with one heuristic identifying it as a link farm on disposable hosting. The document body is heavily obfuscated and appears to be non-readable content, suggesting it's designed to exploit vulnerabilities or redirect users rather than convey information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://salocchi.it/userfiles/files/55588301804.pdf In PDF document text
    • http://bsp-oblspl.org/ckfinder/userfiles/files/pakojuva.pdfIn PDF document text
    • http://dichvubaove.online/upload/files/nurunigeguzepijun.pdfIn PDF document text
    • https://egyptsuntours.com/userfiles/files/xozagumunujojutisumetub.pdfIn PDF document text
    • https://intrigantka.ru/images/userfiles/file/2387795075.pdfIn PDF document text
    • http://dissanna.com/temp/fckeditor/file/57905630585.pdfIn PDF document text
    • https://superchills.com/userfiles/file/62667661162.pdfIn PDF document text
    • http://odnoklassniki-files.ru/images/uploads/files/rukekobusisirokef.pdfIn PDF document text
    • http://abwrva.com/uploads/files/7572208053.pdfIn PDF document text
    • https://888nv.ru/userfiles/file/4290057477.pdfIn PDF document text
    • http://scoutpate.com/userfiles/file/bupodafifipikepuxi.pdfIn PDF document text
    • https://butagallery.com/userfiles/files/97775065971.pdfIn PDF document text
    • http://attep.com/home/sandbox/domains/heekee.com.hk/public_html/ckfinder/userfiles/files/welifipaw.pdfIn PDF document text
    • https://steammining.com/userfiles/file/52520489403.pdfIn PDF document text
    • http://studiocalcinoni.com/userfiles/files/43785494111.pdfIn PDF document text
    • https://srmhomes.com/images/bulk_images/files/45306872567.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/243d7dd0bb67beddc2e1816feb3dd4bb/najuvadokuzokoravireji.pdfIn PDF document text
    • https://oklogistic.lv/upload/file/jifekegufe.pdfIn PDF document text
    • http://phukhoabacninh.com/images/files/naweruw.pdfIn PDF document text
    • http://webinaris.net/ckfinder/userfiles/publics/files/3478579129.pdfIn PDF document text
    • https://mehreganimaging.com/images/upload/files/43081380910.pdfIn PDF document text
    • http://bargiel.com.pl/ckfinder/userfiles/files/19134320094.pdfIn PDF document text
    • http://longtra.vn/userfiles/file/xogifivebixamemulif.pdfIn PDF document text
    • https://www.solucionaesp.com/ckfinder/userfiles/files/sapaxup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=open+android+db+file+on+pcPDF 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_off0000d586.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD586 10512 bytes
SHA-256: 8392f6958cf8c46fec613c8b518e04f87b4bee5f65252342d093d6826ff60069
font_01_sfnt_off0000ed44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED44 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010556.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10556 17236 bytes
SHA-256: ff2b6dd13be5a83725edbfbe176060f22ee4a330d0b5dbe876000ccc80076131