Malicious PDF — malware analysis report

Static analysis result for SHA-256 81c1390ccd398641…

MALICIOUS

PDF

81.8 KB Created: 2021-09-09 13:06:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 2114055b5a66d65c5c350de834e9cf9d SHA-1: 0ec6897b0d5607fa07629b20572f21563652ff84 SHA-256: 81c1390ccd39864140cd97fbb5cc3183814636517ef57c01afbd255d3ace5d1b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised websites and disposable hosting, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated, preventing analysis of its specific content, but the heuristic firings strongly suggest a malicious link aggregation strategy.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://primebrokeragetx.com/ckfinder/userfiles/files/59252404125.pdf In PDF document text
    • https://xrtradingfeedback.com/cmsimages/file/8223073199.pdfIn PDF document text
    • https://augsburger-dartliga.de/uploads/file/gesafapexurizifedux.pdfIn PDF document text
    • https://luxm.pl/userfiles/file/40268280178.pdfIn PDF document text
    • https://prettygreekvillas.com/admin/fckeditor/editor/filemanager/connectofile/51045861291.pdfIn PDF document text
    • http://focalthai.com/file_media/file_image/file/sigevagudi.pdfIn PDF document text
    • https://vr-spagna-20.effievirtual.com/galeria/files/rurinewajod.pdfIn PDF document text
    • https://vespaclubcagliari.com/userfiles/file/3433527097.pdfIn PDF document text
    • https://doctmcooper.com/userfiles/files/dedafazidesavodimujerudo.pdfIn PDF document text
    • https://zibarajabi.com/cache/fck_files/file/68709927936.pdfIn PDF document text
    • https://ruta.hu/ckfinder/userfiles/files/21291087703.pdfIn PDF document text
    • http://aucoindeshalles.fr/menu/file/givapupiwexo.pdfIn PDF document text
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/b0f3465a4047f16d4c97d9f35a3c0a4a/wojixatunom.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/82cb397cf42841c25a6962ffc0ca6534/lasinamowulirunot.pdfIn PDF document text
    • https://www.nhabe.com.vn/ckfinder/userfiles/files/fopikanejigidikegu.pdfIn PDF document text
    • http://askaudit.ru/price/45879054367.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/gexirofijilefirugos.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/rhvg9u8st02dtmrjlhkutpltpa/vozig.pdfIn PDF document text
    • http://prestopc.it/upload/file/27426327726.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133413865368---lijulizoxanu.pdfIn PDF document text
    • http://www.liveartsaskatchewan.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fd9e03227e---54140352712.pdfIn PDF document text
    • https://ochronaskory.pl/pliki_user/File/safibiritonezizefedugob.pdfIn PDF document text
    • http://tea-ra.com/user_data/upload/save_image/files/tokuvazanosu.pdfIn PDF document text
    • http://www.leposeur.fr/site/upload/ckfinder/files/sefuja.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=offline+pvp+shooting+gamesPDF 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_off0000dcc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCC1 10796 bytes
SHA-256: d0c384f130fbabeb4f8121deed5d676bec994c04916fda1fa86a8b6c2457dbd4
font_01_sfnt_off0000f57c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF57C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010d8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D8E 17060 bytes
SHA-256: 6dd3616d1619f2b45947f2b98f379e60ee730dca51077c220a4baeff8ef045e0