Malicious PDF — malware analysis report

Static analysis result for SHA-256 98139bba7c3540fb…

MALICIOUS

PDF

81.1 KB Created: 2021-09-08 21:14:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: ab388859010b15db9abb2ab6ecac985d SHA-1: 7e361cb015997a7d11d51a4cd813917b5dc51825 SHA-256: 98139bba7c3540fb70de3163d4608c1ffdddca0a8fb09307069601c371b88599
174 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating malicious intent, including random URL links and being flagged as a link farm on disposable hosting. ClamAV detection and ML classification further support its malicious nature. The presence of a download button lure suggests an attempt to trick the user into downloading a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://cu-mbc.com/ckfinder/userfiles/files/fakunuwituluda.pdf In PDF document text
    • http://montpellier-businessplan.fr/mbp/upload/images/images/upload/ckfinder/gagufunanon.pdfIn PDF document text
    • https://malmospelmanslag.se/userfiles/file/44614243522.pdfIn PDF document text
    • http://flairpens.ru/uploads/files/79804611565.pdfIn PDF document text
    • http://ambulatorioveterinariocigliano.com/userfiles/files/95734390256.pdfIn PDF document text
    • http://roomyab.ir/basefile/roomyabir/files/nakabuvubisutafevodewipaj.pdfIn PDF document text
    • http://5percent-design-action.com/upload/users/files/27604366795.pdfIn PDF document text
    • http://kondicionery-ivanteevka.ru/upload_picture/file/jazetazigurunojuv.pdfIn PDF document text
    • http://geasit.it/userfiles/files/44762414880.pdfIn PDF document text
    • http://sapientgenerator.ru/files/userfiles/files/tonekude.pdfIn PDF document text
    • https://petala.gr/userfiles/file/wabitawiranikunexepomoris.pdfIn PDF document text
    • http://liccuza.ro/stiri_files/file/44428011653.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/cb341ec66f1ffeb6849352caa6aeee33/25676561846.pdfIn PDF document text
    • http://186086.com/upload/files/17934010527.pdfIn PDF document text
    • https://dichvuhappyhouse.com/upload/files/7927983041.pdfIn PDF document text
    • https://agencement-menuiserie-var.fr/stockages/files/tozuwimolomejotuzavawera.pdfIn PDF document text
    • http://csc0898.com/userfiles/file/20210907014909_vl8vac.pdfIn PDF document text
    • http://vigen12.com/userfiles/file/69085647677.pdfIn PDF document text
    • http://isystemlab.com/admin/ckfinder/userfiles/files/xirufaduruladokalef.pdfIn PDF document text
    • https://masukpt2.com/contents/files/8448567381.pdfIn PDF document text
    • http://le-nora.com/userfiles/file/zagunobugadokumipinoliv.pdfIn PDF document text
    • https://daulte.com/ckfinder/userfiles/files/68674840737.pdfIn PDF document text
    • https://interativacorretora.com/fotosempresa/files/98638158047.pdfIn PDF document text
    • http://kxqcgs.net/filespath/files/20210907163842.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=parts+of+speech+in+pdf+downloadPDF 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_off0000d832.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD832 10804 bytes
SHA-256: 9ffee546dd9737594bcfb96c13d29e5f3a3492524a046734bdd19112f32367d0
font_01_sfnt_off0000f119.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF119 17628 bytes
SHA-256: e2ee590a9304420669f50f3393df448c961918a7a7001b1a257c81a0a04dc2a7
font_02_sfnt_off00011ec2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EC2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1