Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1723d89e2d17edb…

MALICIOUS

PDF

85.3 KB Created: 2021-09-12 04:09:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: df96946cc84c65d0b0569b855cc746e9 SHA-1: c9853eac7baa58641e3fe0dbc8ab492cbeec0307 SHA-256: f1723d89e2d17edbcd696f4986650b791da26a1ac5867094dc1f435785156c69
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The file was detected as malicious by ClamAV and an ML classifier, and a heuristic identified it as a browser extension/update installation lure. This suggests a social engineering attack aimed at tricking the user into executing further malicious actions. The document contains numerous embedded URLs, many of which are PDFs hosted on various domains, indicating a potential link farm or distribution mechanism for malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://corpusbg.com/files/fck/file/11893082563.pdf In PDF document text
    • http://edilcfcostruzioni.com/userfiles/files/69184842551.pdfIn PDF document text
    • http://hypotekaprezamestnancov.sk/res/file/4831981414.pdfIn PDF document text
    • http://archiw.bibliotekalesmierz.eu/img/upload/files/vunimobesowin.pdfIn PDF document text
    • http://vrieshorst.nl/images/uploads/file/pikofemutogu.pdfIn PDF document text
    • http://harringtonassociateslaw.com/Test/JabzMedicalBillingService/userfiles/file/kojajopuxiwowuvapisetabak.pdfIn PDF document text
    • http://www.gpkoaee.ru/ckfinder/userfiles/files/11941353842.pdfIn PDF document text
    • http://oldadmin.k12cart.com/media/files/nuvikeped.pdfIn PDF document text
    • http://kgmda.com/upload/files/pabagoliwenuf.pdfIn PDF document text
    • http://futsalcb.cz/picture/vtextu/file/dugedus.pdfIn PDF document text
    • http://sushibelovo.ru/files/51845951322.pdfIn PDF document text
    • http://fujieshubao.com/zk/UploadFile/file/2021091201503573499.pdfIn PDF document text
    • https://suma.ca/upload/editor/file/44339173467.pdfIn PDF document text
    • http://a2kat.ru/userfiles/file/48533651959.pdfIn PDF document text
    • http://robwalker.net/fckupload/file/nevonomorepoke.pdfIn PDF document text
    • http://syntra.pl/userfiles/file/54053034215.pdfIn PDF document text
    • http://chaukitchen.com/uploads/files/16782653334.pdfIn PDF document text
    • http://bebsulmare.com/userfiles/files/59978748718.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/6dfe255e2b88550772558330e72cbf22/7341060614.pdfIn PDF document text
    • https://www.luthier-auxerre.fr/ckfinder/userfiles/files/69957305371.pdfIn PDF document text
    • http://mybed.tw/uploads/files/202109101318591019.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135f16a16a3f---75833115450.pdfIn PDF document text
    • http://didaconcept.com/admin/fckeditor/file/21926620900.pdfIn PDF document text
    • https://gastriklandsbf.se/UserFiles/files/61547853526.pdfIn PDF document text
    • http://mmckno2010.zkosuchdol.info/files/supexasanimowam.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/dezak.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=how+to+copy+apk+to+android+devicePDF 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_off0000e578.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE578 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fd8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD8A 19076 bytes
SHA-256: f3c59f3eb752da3515157802e2acb25a19e69a873e61f5dfbf6ccbb3bd44538a
font_02_sfnt_off00012e8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E8B 10640 bytes
SHA-256: e26058161d3dfb511df592a21c5dfdc76f67a3a5a6f73d4124ab012ae7067e61