Malicious PDF — malware analysis report

Static analysis result for SHA-256 35b1b2c7e781b001…

MALICIOUS

PDF

72.8 KB Created: 2021-09-06 10:52:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 30cefd1afae1197133a4679f452cc142 SHA-1: 42fab1d86026bccf1fb34008961e052c8432bb77 SHA-256: 35b1b2c7e781b001edf4167f8ac4c32dc1fbfaed6ba99020be57ce5b1ac01f5a
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to other PDF files hosted on potentially compromised websites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document's structure as a link farm suggests an attempt to obscure the true malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/160efe815af058---tijelozudolusejonobu.pdf
    • http://medicare-darmstadt.de/bilder/UserImages/file/bewutuf.pdf
    • http://hitelesen.com/userfiles/file/55703029634.pdf
    • http://hataylezzeti.com/resimler/files/tupepelusaxovonesorodixa.pdf
    • http://pdww.ru/ckfinder/userfiles/files/wabeti.pdf
    • http://lotusromeo.fr/app/webroot/files/userfiles/files/wuxetironurigulupezav.pdf
    • https://nucamsa.es/userfiles/files/79597581822.pdf
    • https://mecaniquekd.ca/upload/file/widuxewerubemokajajis.pdf
    • http://fzcce.com/aimgs/uload/files/rinivapurabulazetewapegam.pdf
    • http://easternhoteljeju.com/FileData/ckfinder/files/20210817_F9E5E4B1860061B5.pdf
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e12e873126e---88497588969.pdf
    • https://familienarbeit3plus.ch/userfiles/files/nepiluvanujilipebikax.pdf
    • http://insuralead.com/userfiles/file/jepibumu.pdf
    • https://eatorhours.org/e-bussiness/fckimages/file/52261357338.pdf
    • http://fitnessklub-impuls.pl/uploads/assets/file/13872878977.pdf
    • http://fohow77.ru/upload/file/38096928837.pdf
    • http://baigeleather.com/userfiles/file/9115568106.pdf
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/1da159b0d6a452fb0bd9a5cc7f3606a4/84318945053.pdf
    • http://cu-hinothai.com/ckfinder/userfiles/files/16955207300.pdf
    • http://cleannshieldflorida.com/wp-content/plugins/super-forms/uploads/php/files/9e3056d0de30273c01e6d10bddb70d33/xagop.pdf
    • http://digitalqwerty.com/ckfinder/userfiles/files/vazajez.pdf
    • https://www.highlandernepal.com/assets/ckfinder/userfiles/files/5744997000.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=area+of+similar+figures+worksheet
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b92b.bin
b30424a1840abdc4250d53df1625c14173c82a36e0c31d7d6f53b1adfd4f9fd3
pdf-font-stream PDF embedded font (sfnt) at offset 0xB92B 10816 bytes
font_01_sfnt_off0000d23e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD23E 16792 bytes
font_02_sfnt_off0000ea50.bin
fbe0121334adb8903af9d6a5c316b74feccc2eecab12c9a65b10ea636a638660
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA50 16892 bytes