Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cb24dc46f2d856f…

MALICIOUS

PDF

84.8 KB Created: 2021-09-18 04:49:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0a650256854cb7e676f31cd360282818 SHA-1: 043d3b218fdde9d906c4aefcfe5c9b61a6ebfa48 SHA-256: 4cb24dc46f2d856f2050a3f97bad6bed82263ea9237e82cf7d5e6504ac201994
156 Risk Score

Malware Insights

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

The file was identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. Multiple URLs point to compromised CMS upload directories and disposable hosting, suggesting an attempt to lure users to malicious sites. The PDF structure and embedded URLs strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://dermatologie-chamonix.com/userfiles/file/fezifod.pdf In PDF document text
    • http://ojazzdance.fr/userfiles/file/81324061001.pdfIn PDF document text
    • http://konikanarrowfab.com/ckfinder/userfiles/files/8209734907.pdfIn PDF document text
    • https://gancza-yacht.pl/userfiles/file/xajuziregapi.pdfIn PDF document text
    • https://asset-books.com/userfiles/file/zetox.pdfIn PDF document text
    • http://cokhixnktientien.com/Images_upload/files/55486102356.pdfIn PDF document text
    • http://imosa.asia/uploads/files/202109091424181673.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16130e7e41efb8---66694392719.pdfIn PDF document text
    • https://bluetact.com/locktactyuma/userfiles/file/50317384250.pdfIn PDF document text
    • http://fsoa.cn/userfiles/file/78977462997.pdfIn PDF document text
    • https://tradingphrases.com/userfiles/files/zijipojezuxuwaso.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161314b79f35f4---lebekekokaz.pdfIn PDF document text
    • http://technestudio.eu/userfiles/files/78216373943.pdfIn PDF document text
    • http://tareeapartment.com/user_img/files/65206895022.pdfIn PDF document text
    • http://vanillasky-ch.com/images/files/65430948361.pdfIn PDF document text
    • http://e-photo.lv/ckfinder/userfiles/files/kedupuwegikudekeze.pdfIn PDF document text
    • https://girilawfirm.com/content_files/files/sotiraxujolokavetenenamob.pdfIn PDF document text
    • http://rasmesafar.net/basefile/basefiles/gipuvimamoruririka.pdfIn PDF document text
    • http://smartvoicesys.com/userfiles/kosotupatezerizabiki.pdfIn PDF document text
    • http://baove24h.info/upload/files/siwagunevavedipu.pdfIn PDF document text
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/16142250d65e86---78912122257.pdfIn PDF document text
    • http://good163.cn/Uploadfiles/files/duvisinov.pdfIn PDF document text
    • https://yodishit.com/uploads/userfiles/file/komiragurijukabo.pdfIn PDF document text
    • http://canigrup.com/userfiles/file/peburodozitifeti.pdfIn PDF document text
    • http://cappellastudio.it/userfiles/files/32075226735.pdfIn PDF document text
    • http://xfswchem.com/upload/files/48040108690.pdfIn PDF document text
    • http://greenhere.cn/upload/ckimg/files/202109060249513506.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=add+keyboard+to+android+phonePDF 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_off0000e754.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE754 10604 bytes
SHA-256: 78d2c606426fa5a2a20a5974a0ccc45038d2056e6b238ce49e5281e0d84cc827
font_01_sfnt_off0000ff41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF41 17696 bytes
SHA-256: bf6dfdb76f525cdee470ce460d841fe3699179c1b3e2735c319dd057ea3c6c72
font_02_sfnt_off00012d9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D9F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1