Malicious PDF — malware analysis report

Static analysis result for SHA-256 88bd5dcb0ed92f26…

MALICIOUS

PDF

76.8 KB Created: 2021-09-09 10:21:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 040e82d254af58d71afc5c9972e3f876 SHA-1: 7954dc314ba348764e281fa5d393fda8f3288179 SHA-256: 88bd5dcb0ed92f26acd204ef22415b87f54a23e9935e3a84bbfb87c2dae20dd8
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains multiple external links, with several heuristics indicating it functions as a link farm on disposable hosting. The ClamAV detection and ML classifier strongly suggest malicious intent, likely to redirect users to phishing sites or download further malware. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://nomylo.ru/uplcv?utm_term=sandman+volume+2+pdf PDF link annotation
    • https://attackworkoutprogram.com/app/webroot/files/ckfinder/userfiles/files/kosegatewazarokawagek.pdfIn PDF document text
    • http://hiredriver.com/uploads/assets/files/71784846635.pdfIn PDF document text
    • https://mudrun.com/home/mud/public_html/ckfinder/userfiles/files/begadilinijoxexobolas.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/csqc9hg5av2f4nrsmqga1tqino/furuwutowiseg.pdfIn PDF document text
    • http://timnhanhonline.com/upload/files/65136075753.pdfIn PDF document text
    • https://razredna-nastava.net/files/96157160348.pdfIn PDF document text
    • http://modnyi-buket.ru/uploads/files/38188199267.pdfIn PDF document text
    • https://aneri12.eu/res/file/82843900329.pdfIn PDF document text
    • http://poultech.net/d/files/pinemilazakimefagiwelidod.pdfIn PDF document text
    • http://e-store-sys.com/userfiles/file/76014707925.pdfIn PDF document text
    • https://blueparadise.pl/userfiles/file/70477695478.pdfIn PDF document text
    • http://9y.bfage.com/upload/files/20210907145000.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/1613125848bc43---sulukajidepevozam.pdfIn PDF document text
    • http://studiotecnicostradi.eu/userfiles/files/46253710779.pdfIn PDF document text
    • https://petpetmates.com/files/editor/file/62222593369.pdfIn PDF document text
    • http://taigesw.com/upload/files/bojolo.pdfIn PDF document text
    • https://volnynaklad.cz/data/file/9415065843.pdfIn PDF document text
    • http://educasters.co/ckfinder/userfiles/files/21427364009.pdfIn PDF document text
    • https://istanajp.com/contents/files/90788676598.pdfIn PDF document text
    • http://sdv.sk/userfiles/articles/file/71650172253.pdfIn PDF document text
    • https://vhcvietnam.vn/ckeditor/images/files/13933246750.pdfIn PDF document text
    • https://stthomasorthodoxchurchsouthpampady.com/userfiles/file/damige.pdfIn PDF document text
    • http://gardensyellowcab.com/admin/images/file/97524868695.pdfIn PDF document text
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/93ba05ad500a7cecf0a530b24cb2fc3b/botezowisenaguxuj.pdfIn PDF document text
    • https://tes-sys.com/uploads/ckfinder/files/20210906/16309121522343.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_off0000c87b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC87B 17528 bytes
SHA-256: 4a33e6845fda7c4644487d7cf27ba8748eff036811275002f5f399ab94115486
font_01_sfnt_off0000f573.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF573 10560 bytes
SHA-256: 6f77180acff9d3ab660221eec61c825f8838cdb565b5644129edc89858c49783
font_02_sfnt_off00010d98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D98 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1