Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4f0cfb729778676…

MALICIOUS

PDF

77.0 KB Created: 2021-09-03 12:43:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: b7e662188f0059411f7c1a390a380045 SHA-1: 99137469861de50f95f476d01e1881c33b690781 SHA-256: a4f0cfb7297786765875a2f3659c9b051444d37d20d5ba066274487011e7e1ee
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to numerous external URLs, many hosted on compromised websites, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of malicious activity, likely leveraging T1566.001 (Spearphishing Attachment) as an initial access vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://ontech.vn/images/ckeditor/files/67711353051.pdf In PDF document text
    • http://fatamorgana.fr/uploads/assets/file/leneraxexojaxupuda.pdfIn PDF document text
    • http://akicgiyim.com/userfiles/file/68516036132.pdfIn PDF document text
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607060825fc4d---logulirowo.pdfIn PDF document text
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/3l2fh9mfbjku338j91tdi1msem/47163003651.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/93711956964.pdfIn PDF document text
    • http://fautographie.org/images/userfiles/files/wubir.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16070d4fd7fcd3---rujosefakikedof.pdfIn PDF document text
    • http://quartierdete.fr/uploads/fckeditor/file/75137328177.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/patagejobuviji.pdfIn PDF document text
    • http://hart-metale.pl/gimnazjum/userfiles/file/43884036754.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b205f738ccf---forefitof.pdfIn PDF document text
    • https://thefencedocumentary.com/adminfiles/file/98344295328.pdfIn PDF document text
    • https://wic-net.com/userfiles/file/fikejusamatiwaj.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/3683611cdbc88ba68c2f0bc7b1e21e78/majalevakomevuladurup.pdfIn PDF document text
    • https://pametnidom.hr/pametne_kuce/userfiles/file/31117505062.pdfIn PDF document text
    • https://gloriamus.org/Uploads/userfiles/files/90571661103.pdfIn PDF document text
    • http://e-kva.ru/admin/ckfinder/userfiles/files/26311797714.pdfIn PDF document text
    • http://matstravel.ru/userfiles/file/gafofavubi.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607536df4a99f---35932005797.pdfIn PDF document text
    • http://www.oneworldkarate.com/fckeditorimages/userfiles/file/jelif.pdfIn PDF document text
    • https://mclandpin.com/calisma2/files/uploads/42435387794.pdfIn PDF document text
    • http://abwingsva.com/uploads/files/54596934098.pdfIn PDF document text
    • http://raunlarose.us/wp-content/plugins/formcraft/file-upload/server/content/files/1608dfc3dad460---86573332092.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160879da9ae700---61215489047.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=liver+fluke+in+sheep+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_off0000cadf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCADF 17092 bytes
SHA-256: caabd2a9b213071a926ee693242d2bf1bc5bbb87e6211458c0b3524ec90dc7a8
font_01_sfnt_off0000f6e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6E9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010f00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F00 10432 bytes
SHA-256: fcd820bb00e9db86df1dcfdbcc08adaf2c19212073f028f0725f5e3b025e5021