Malicious PDF — malware analysis report

Static analysis result for SHA-256 83bc4537b6b8da79…

MALICIOUS

PDF

94.3 KB Created: 2021-10-11 11:51:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 2dd1ad596979f5976d1efef63ae72dc1 SHA-1: 5af8888901480897e15753ff7d4a61d1ebe0daab SHA-256: 83bc4537b6b8da7900d8495a1a7e3ab90c23e2eee87ca6f01ef359447c6d234d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document contains numerous links to disposable hosting, suggesting a phishing or malware distribution scheme. While no scripts were directly extracted, the presence of embedded URLs and the nature of the heuristics point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://alles-vom-schreiner.de/userfiles/file/lofanabutavil.pdf In PDF document text
    • http://pizzeriagiganti.ro/imagini_ws/14976354416.pdfIn PDF document text
    • http://yoron.net/up/files/kofesaseviduno.pdfIn PDF document text
    • http://apnschool.in/singhania/downloads/file/39830667808.pdfIn PDF document text
    • http://dsagco.com/Upload/file/56339413371.pdfIn PDF document text
    • https://rajatotogroup3.com/contents/files/vitenuzutisog.pdfIn PDF document text
    • https://arbormaster.net/uploads/files/73822201281.pdfIn PDF document text
    • https://verner.lt/images/files/80340944128.pdfIn PDF document text
    • http://hoangle.vn/uploads/userfiles/file/tosuru.pdfIn PDF document text
    • https://abisspaandboutique.com/nbloom/fckuploads/file/nawijevizut.pdfIn PDF document text
    • https://panama4d.com/contents/files/nuwojiwunuzimeto.pdfIn PDF document text
    • http://cjmfgxfollow.morefriendship.com/upload/files/fezavipavefolopulovod.pdfIn PDF document text
    • https://mkserwis.pl/userfiles/file/veranadegusabifijetad.pdfIn PDF document text
    • http://xiangzhuan.tw/upload/files/fixiteserupowulenejid.pdfIn PDF document text
    • https://bgg.pirkitpadangas.lt/ckfinder/userfiles/files/90295783815.pdfIn PDF document text
    • http://galettedesrois.hu/userfiles/file/xejuzudugupubegafomerul.pdfIn PDF document text
    • https://desco.scp.hr/files/wileledonurexizuxu.pdfIn PDF document text
    • http://wimborst-ceramics.nl/ckeditor/ckfinder/userfiles/files/ripuzudekavap.pdfIn PDF document text
    • http://tuzoltosagmihald.hu/userfiles/file/86360147745.pdfIn PDF document text
    • https://xn--hjrnskadeakademien-mtb.se/userfiles/file/19701275155.pdfIn PDF document text
    • https://incoyun.com/calisma2/files/uploads/paniful.pdfIn PDF document text
    • https://spitalmoldovanoua.ro/ckfinder/userfiles/files/sapoxena.pdfIn PDF document text
    • http://billsky.ee/files/file/10349806070.pdfIn PDF document text
    • https://astdubai.co/userfiles/files/bolipuguxafidow.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/7xhmvLXWVJc/uplcv?utm_term=the+walking+dead+a+new+frontier+apkPDF 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_off000102c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102C8 10752 bytes
SHA-256: fa6090523f4cfb4204ecc55fc7dcc882cf47f42711a9583b586a10cbbd19a7bf
font_01_sfnt_off00011b46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B46 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013358.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13358 21308 bytes
SHA-256: 317462d0298e93a4c04568b9017fcab3105492dac067f93f93ca113943875db4