Malicious PDF — malware analysis report

Static analysis result for SHA-256 017bffac23f41a86…

MALICIOUS

PDF

68.2 KB Created: 2021-09-29 08:14:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 758a31744089dc2c30a3ef2a2157d95b SHA-1: 3c7b5829de83cdaab043bc79086b61d3452b5b1c SHA-256: 017bffac23f41a868cb5f5fd0e4ff8225aa48933a74be166eac7db7c07c9800e
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple heuristics indicating it is a link farm designed to redirect users to other PDFs, with one high-severity heuristic pointing to a suspicious URL. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

Heuristics 6

  • 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.
  • 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://narcisse.sk/editor_uploads/files/toxipudulokoraluvegol.pdf In PDF document text
    • http://leeharringtonhomes.com/userfiles/file/rifizu.pdfIn PDF document text
    • http://nfrostov.ru/upload/files/lejojesisolomobiwovekulil.pdfIn PDF document text
    • http://aan.kz/ckfinder/userfiles/files/zapugexasegadawegakili.pdfIn PDF document text
    • http://highendschmiede.de/highendfiles/file/15826381027.pdfIn PDF document text
    • https://parlagame.com/calisma2/files/uploads/42813901903.pdfIn PDF document text
    • http://volareinmongolfiera.it/userfiles/files/wugidusodexibibalib.pdfIn PDF document text
    • https://internationallanguagenavigators.com/media/53257157619.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/161371d19a7820---regalutegera.pdfIn PDF document text
    • http://n3ss.ro/ckfinder/userfiles/files/vetovaxexitova.pdfIn PDF document text
    • http://www.uc-kushiro.net/images/library/File/86271689237.pdfIn PDF document text
    • http://teewer.mn/ckfinder/userfiles/files/fanulogidudunolod.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614590ea76868---tanut.pdfIn PDF document text
    • http://belstroyiz.ru/img/file/tujipite.pdfIn PDF document text
    • https://muguet.fr/sites/default/files/file/detes.pdfIn PDF document text
    • https://pecintajp.com/contents/files/85311558668.pdfIn PDF document text
    • http://slxiang.com/v15/Upload/file/20219112231232010.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/96353616391.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1614cb426b1443---92825255393.pdfIn PDF document text
    • http://ldksolar-officialliquidation.com/userfiles/files/26921501037.pdfIn PDF document text
    • http://beautifulmoda.com/userfiles/files/87932698128.pdfIn PDF document text
    • http://cuspsurgeons.com/userfiles/file/wemebub.pdfIn PDF document text
    • https://at-studio.tw/app/webroot/userfiles/files/20210909_161814.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=angry+birds+2+2021PDF 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_off0000ae04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE04 15128 bytes
SHA-256: db4b84e2bdfa98fd3cd039c90677533e014d3e9275b17cf6f8c77f44e4f36141
font_01_sfnt_off0000d434.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD434 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ec4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC4B 10396 bytes
SHA-256: 1e6ee74574697c40c9781e790f6f0a41ccccd85c2f3c55ec44ddebcdc0ec10f1