Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4b34feaf2b9c974…

MALICIOUS

PDF

70.6 KB Created: 2021-09-06 01:11:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c94b0ab48b753af2fe1e2175cf1bfd19 SHA-1: 872679c09ea8b44ea0f1c6f8f84d794f01049b0d SHA-256: a4b34feaf2b9c9748a7f4b74be8ba0c8e4620e1bbf571d401185dfe1f8be4c61
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate it functions as a link farm, directing users to compromised websites, which is a common tactic for phishing or malware delivery. The presence of multiple unknown and potentially compromised URLs supports this attack pattern.

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://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/771eac424e420c16469085e48b0c26eb/6157804762.pdf In PDF document text
    • http://www.salac.cz/ckfinder/userfiles/files/28111859105.pdfIn PDF document text
    • https://europawindow.com/app/webroot/img/main_content/files/52961131700.pdfIn PDF document text
    • https://tenshinorchids.com/FCKeditor_upload/file/fixemo.pdfIn PDF document text
    • http://www.microsinusectomi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607625606b7e8---19599797564.pdfIn PDF document text
    • https://www.bocamvigliesrooms.com/wp-content/plugins/super-forms/uploads/php/files/9c645f7491e068f6190f617b272e45f4/68829315347.pdfIn PDF document text
    • https://namdolove.com/FileData/ckfinder/files/20210812_EC4A0C49A5272CE2.pdfIn PDF document text
    • https://engineeredrepinc.com/wp-content/plugins/super-forms/uploads/php/files/a900418c91c9d04f5147455d7b2f9a34/lisutogudedemujetoroziki.pdfIn PDF document text
    • https://nutricount.cz/UserFiles/File/joberodaboroj.pdfIn PDF document text
    • http://csc0532.com/userfiles/file/20210702071930_fmal18.pdfIn PDF document text
    • https://goldmenu.com/userfiles/file/kebariletetudadosasafa.pdfIn PDF document text
    • https://valubil.com/public/uploads/cms_file/cms_files/41985642654.pdfIn PDF document text
    • http://spec-so.ru/sites/default/files/file/4455464695.pdfIn PDF document text
    • https://educhina.mn/editor/files/25074188586.pdfIn PDF document text
    • http://pijntherapie.be/uploads/files/dekej.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/luragovopibojapugisajibu.pdfIn PDF document text
    • http://dangkydoanhnghiep.org/hinhanh_fckeditor/file/javilososuzomigaj.pdfIn PDF document text
    • https://digireg.se/upload/bagebotuvadoj.pdfIn PDF document text
    • https://gloriouz.in/ckfinder/userfiles/files/77187832698.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/ou8le0j05nvame4tb9ng0oki0o/lapofixaratujisiju.pdfIn PDF document text
    • http://phoiinnhiet.com/images/uploads/files/4526546472.pdfIn PDF document text
    • https://nguyenvanhuongloc.vn/app/webroot/files/images/pages/files/96721196798.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=livro+processo+civil+didier+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_off0000b5eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5EB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE02 10272 bytes
SHA-256: d702ecdcbdc8f2dfe856ae1c7130d114f01dccdc52720de79208b3e585da10c2
font_02_sfnt_off0000e52c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE52C 15692 bytes
SHA-256: ed621295ea4c1d50bc1abe3781f4af39a798d430c32bf14a9d0d339d03e70cbf