Malicious PDF — malware analysis report

Static analysis result for SHA-256 d681dc5d5044de0b…

MALICIOUS

PDF

80.0 KB Created: 2021-09-20 17:07:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 92ea444338dcf0b9532e8eb6a4704fbe SHA-1: dc08857759595b7a215fa2aeec86ad56fceb6f2f SHA-256: d681dc5d5044de0bb590eacc2e1a01404d4816dd65f0719114594c2deab84b10
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Several heuristics indicate the PDF functions as a link farm, with many embedded URLs pointing to compromised WordPress upload directories and disposable hosting. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure and URL analysis strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141b06daa192---kunodazubozurep.pdf In PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1614408715b9a2---22110957033.pdfIn PDF document text
    • http://okna-stv.ru/userfiles/files/59094977621.pdfIn PDF document text
    • http://xn----7sbezcba9a5aggb3j.xn--p1ai/ckfinder/userfiles/files/8228397087.pdfIn PDF document text
    • https://aczv.fr/userfiles/file/nozodesuberejidi.pdfIn PDF document text
    • https://equalland.com/uploads/File/68373816317.pdfIn PDF document text
    • https://www.oalysa.cz/ckfinder/userfiles/files/letefawisoxoxetimowonekif.pdfIn PDF document text
    • http://vcelari.naceradec.cz/includes/ckfinder/userfiles/files/kaxefavodegivuwiwitariwa.pdfIn PDF document text
    • http://zkqzl.com/uploadfile/file///2021090410215285.pdfIn PDF document text
    • http://innobiztour.com/FileData/ckfinder/files/20210911_17098EAC3A572613.pdfIn PDF document text
    • http://hyunsin.net/userfiles/file/55146782107.pdfIn PDF document text
    • http://motovelo-nmsk.ru/userfiles/file/905943418.pdfIn PDF document text
    • http://ohsongpharm.com/ckfinder/userfiles/files/41147534176.pdfIn PDF document text
    • http://sanxuatbanthinghiem.org/app/webroot/uploads/files/98711792135.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/161308521864ca---74476991487.pdfIn PDF document text
    • http://asbazainville.org/userfiles/file/9464509069.pdfIn PDF document text
    • http://blekinge.boj.se/uploads/userfiles/files/2721990866.pdfIn PDF document text
    • http://clinton.abwingsmd.com/uploads/files/85294630859.pdfIn PDF document text
    • https://limberhurstgallery.com/imageuploads/file/31625950721.pdfIn PDF document text
    • http://metalltechnik-kutschi.at/41730014701.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16140e82931c8c---duzowavupin.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=game+speed+apkPDF link annotation
    • https://lapdonline.org/file/45877762183.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_off0000d840.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD840 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f057.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF057 10124 bytes
SHA-256: 25f7cec28519bb4f1016578aa9c4710690ef00022209bb7b167bcaa74c4b6001
font_02_sfnt_off000106f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106F5 16972 bytes
SHA-256: 94e3ab6ff818660aa2541ada91c0885dcb8f0c671c8f34619425a0b1243b62bb