Malicious PDF — malware analysis report

Static analysis result for SHA-256 b25fff54dca92418…

MALICIOUS

PDF

71.4 KB Created: 2021-09-25 14:01:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4eff90f694d1e5475961b411b91174fd SHA-1: 9a0fb84a0cd17d30ac9767c4e6940a3ea2891cfe SHA-256: b25fff54dca92418e5710eee8292dd0ade63055aa3c5339b9913c447224461d6
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and numerous links to external URLs, many of which are algorithmically generated and hosted on disposable domains. This strongly suggests a phishing or malware distribution campaign, where the PDF acts as a lure to redirect users to malicious sites. The ML classifier and ClamAV detection further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://inwebjor.ru/uplcv?utm_term=wps+apk+english+version PDF link annotation
    • https://bloomland.com/sites/bloomland.com/files/mifegilunevujenaxunip.pdfIn PDF document text
    • http://budaors.varosom.hu/userfiles/files/taniji.pdfIn PDF document text
    • http://universalthailand.com/images/uploads/ckfinder/files/96706224735.pdfIn PDF document text
    • https://alexandrapanayotou.com/web/images/static/file/31935268800.pdfIn PDF document text
    • https://allmassage.net/upload/file/20210901165235.pdfIn PDF document text
    • https://www.beadvised.co.uk/wp-content/plugins/super-forms/uploads/php/files/3abebfb8ed6a5276061ae3b68a78ee3b/bujotuxemikorupunixisuge.pdfIn PDF document text
    • http://rigassprotes.lv/uploadz/file/52806267022.pdfIn PDF document text
    • http://epoxidice.ro/mm/file/fewulitowelexolinuxulibi.pdfIn PDF document text
    • http://abwessex.com/uploads/files/68048526932.pdfIn PDF document text
    • https://dreptultau.hotnews.md/upload/userfiles/files/zogobapoj.pdfIn PDF document text
    • https://www.carnesvarejo.com.br/assets/ckfinder/core/connector/php/uploads/files/nudinusop.pdfIn PDF document text
    • http://pronobile.com/catalog/file/sofetubafebebojevomubusu.pdfIn PDF document text
    • http://csptech.net/admin/userfiles/file/43942553075.pdfIn PDF document text
    • https://mmeasar.com/mmeasarfiles/file/41624477651.pdfIn PDF document text
    • http://gelateriacool.it/userfiles/files/widigetede.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/16131af063d942---vozawugupitumu.pdfIn PDF document text
    • http://autosvanbeek.nl/mindcms/js/ckf/userfiles/files/23573048153.pdfIn PDF document text
    • http://sevinctekstil.com/resimler/files/39285267235.pdfIn PDF document text
    • http://rnralpha.cz/res/file/jugeguborami.pdfIn PDF document text
    • https://ka-base.no/images_content/file/xuwowu.pdfIn PDF document text
    • http://jinruily.com/UploadFile/file/20210914184843410.pdfIn PDF document text
    • https://nezrenweb.com/calisma2/files/uploads/731976919.pdfIn PDF document text
    • http://veterinarioassociatopacinidallatorre.eu/userfiles/files/29197530812.pdfIn PDF document text
    • http://www.farmaciapenil.es/userfiles/files/10547439036.pdfIn PDF document text
    • http://studiomedicoveterinariobellucci.eu/userfiles/files/kugeroteba.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_off0000b2e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cafc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAFC 10584 bytes
SHA-256: 9aa65884393dac301c60bd69c272934d14288304fb1f5b305d3689d512b97051
font_02_sfnt_off0000e31b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE31B 17696 bytes
SHA-256: 18f562240397fd82160e7e65e982504de44cf0afbb620c4f0056c10e4bb3b02e