Malicious PDF — malware analysis report

Static analysis result for SHA-256 23d48aec2a5d8f79…

MALICIOUS

PDF

69.4 KB Created: 2021-10-02 12:52:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: b28aa5d8327b8da6d166c1c51659e8cb SHA-1: 754bd6b8e7f1bb3f74c1f7eca9b52e1d1bb9dab9 SHA-256: 23d48aec2a5d8f79c002f93d4c63e6b07b0d6286ea3e12d298e1751512a53816
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious content or initiating phishing attacks. The PDF also includes numerous external links, several of which point to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to obscure the ultimate destination or host malicious files. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615808a63c650---pufusunibibemo.pdf In PDF document text
    • https://hzautomatisering.nl/userfiles/file/supososubivevaxunafoto.pdfIn PDF document text
    • http://saraiaser.nl/userfiles/file/83280308432.pdfIn PDF document text
    • http://tahi.hu/ckfinder/userfiles/files/minovimiboza.pdfIn PDF document text
    • https://ataru.site/js/ckfinder/userfiles/files/71704039609.pdfIn PDF document text
    • http://www.egavilanes.com/ckfinder/userfiles/files/lamatof.pdfIn PDF document text
    • http://cncforginghammer.com/d/files/nasugutoma.pdfIn PDF document text
    • http://bochkari24.ru/pic/file/rulugaxed.pdfIn PDF document text
    • https://4of100churchstreet.com/assets/media/files/9643287346.pdfIn PDF document text
    • http://police8coop.com/UserFiles/file/19771259096.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/fc43798b65742f1ade8c1927f78df2dd/75703420150.pdfIn PDF document text
    • http://szyuangang.com/UserFiles/file///28645754213.pdfIn PDF document text
    • http://lj-group.cn/upload/files/61921717557.pdfIn PDF document text
    • https://vipbeachhouse.com/uploads/editor/file/71897018646.pdfIn PDF document text
    • http://hoteldanang.com/uploads/images/files/7965891784.pdfIn PDF document text
    • http://aardbeienfeesten.nl/uploadimages/files/bevas.pdfIn PDF document text
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613967d450c17---33702808505.pdfIn PDF document text
    • https://xcheck.vn/uploads/userfiles/file/43382376860.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=negative+fractional+powersPDF 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_off0000ac88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAC88 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c49f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC49F 10784 bytes
SHA-256: 94bcfed804f2981e81f508c4ebe8c24ee3e83c76f217cb116fca09534b52ca67
font_02_sfnt_off0000ddad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDAD 16696 bytes
SHA-256: 1ee7d38d75e9e79a32a3fe32232b96abf06afca48a595fca485d289307386395