Malicious PDF — malware analysis report

Static analysis result for SHA-256 499a3fdf517ce11c…

MALICIOUS

PDF

78.0 KB Created: 2021-09-07 01:22:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 2ff41ad6496ee01d5cd96428bfae08ff SHA-1: fc8320b1443e1f7d45f36e8e6e43abf4304dc260 SHA-256: 499a3fdf517ce11c5395f6a9fde2488207391672ad576c716b5b96cd06e68ddf
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of embedded JavaScript and a link farm pointing to compromised WordPress uploads suggests the document is designed to redirect users to malicious content or facilitate further compromise. The primary attack pattern involves leveraging these links and scripts to potentially download a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://empezo.xyz/js/ckfinder/userfiles/files/xazuxukudisegun.pdf In PDF document text
    • http://nsfeed.com/_UploadFile/Images/file/15015678013.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a702562b1e9---topovexisosojotagibu.pdfIn PDF document text
    • http://museeducuir.org/upload/files/tibibo.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/966d4g85c4ovasf6ubns6rjlo2/39683484907.pdfIn PDF document text
    • http://serextion2006.com/js/upload/files/bumerabu.pdfIn PDF document text
    • http://www.sun-green.eu/ckfinder/userfiles/files/jinividoxekisubijutegopo.pdfIn PDF document text
    • http://hotararicedo.ro/files/files/53798362721.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee908d2acdf---kufoxuwel.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ba65e279a6c---xuduxupejoda.pdfIn PDF document text
    • https://kga-am-adlergestell-ev.de/kga/ckfinder/userfiles/files/40071510788.pdfIn PDF document text
    • http://lotusburbank.com/uploads/files/73028809441.pdfIn PDF document text
    • https://thibiditrading.com/public/userupload/files/87568467349.pdfIn PDF document text
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/36386774593.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a951c3a95cc---simatifomapupo.pdfIn PDF document text
    • https://acgroupenterprise.com/userfiles/file/64833491039.pdfIn PDF document text
    • http://hdurmuslar.com/images_upload/files/15942155938.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/44159908804.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=suzuki+grand+vitara+2011+manual+pdfPDF 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_off0000c988.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC988 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e19f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE19F 11108 bytes
SHA-256: 9fb41551a7e5ce969c503f1814e18ff71771e74c315edceb46dc13da73dd8338
font_02_sfnt_off0000fb75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB75 17720 bytes
SHA-256: cd4e88f660054d95fcd47ebeac2607633f310747cbf5114b77e8567a663fea3e