Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6cb90fccb645c16…

MALICIOUS

PDF

81.8 KB Created: 2021-09-05 10:01:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 51993916f183b0ca9abb086f9d5e8b2e SHA-1: 158f2b9beebcb5d5d14e955fa9ab34234dbf550a SHA-256: a6cb90fccb645c16a2c46add44ee479737f69943bf6e08ef4d3e338a7495ff92
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://laborke.ru/uplcv?utm_term=chemical+bonding+pdf+grade+9 PDF link annotation
    • http://anpo.vn/upload/files/60296708450.pdfIn PDF document text
    • https://impresa-valli.it/file/lejifiwitefololam.pdfIn PDF document text
    • https://milsagliksen.org/upload/ckfinder/files/11281719089.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/173bff463b6d5451b722e1cbb5cdafb8/kusekeserovoj.pdfIn PDF document text
    • http://erdivigado.hu/userkepek/file/46985248058.pdfIn PDF document text
    • http://arohitourandtravels.com/userfiles/file/nigugipawoti.pdfIn PDF document text
    • https://nhachoxebus.com/upload/fck/file/zimizon.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c52006cceed---49937307226.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc1841c2a0---radisovasomosexejexajuzo.pdfIn PDF document text
    • https://www.bocamvigliesrooms.com/wp-content/plugins/super-forms/uploads/php/files/ec55e3c78ffcc0bced0e788ff61d8eb4/44339244261.pdfIn PDF document text
    • http://softwarefactory.nl/images/file/32327398299.pdfIn PDF document text
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/41a56678b90b70637979d7b0800d74da/26757356692.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/rnbmnge3vtj0m0qbhrq2kih896/dedutuk.pdfIn PDF document text
    • https://shiphangnhanh.net/uploads/image/files/jifemewimesusewubag.pdfIn PDF document text
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/sdu9cqq5vt8rna870t2i7f59n4/nufoteruletirojetawi.pdfIn PDF document text
    • https://adasms.fr/userfiles/file/fuxenobo.pdfIn PDF document text
    • http://almar-bus.pl/userfiles/file/19412111176.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/f424b4dc3f3a55301ec460f8e7458360/55811742541.pdfIn PDF document text
    • http://pokorny-podlahy.cz/UserFiles/File/11597984487.pdfIn PDF document text
    • http://perfectionistpaintingnj.com/ckfinder/userfiles/files/82028171441.pdfIn PDF document text
    • http://tuvanluatdanang.com/upload/ck/files/nedexejubuzedasorope.pdfIn PDF document text
    • 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_off0000dc17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC17 17108 bytes
SHA-256: 65a4712ba2ffba44a9f92adfc9b2b9f23a9d4936da9196859dfff3690f9d4170
font_01_sfnt_off00010848.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10848 11140 bytes
SHA-256: 78822c3fec3b9dc45e0d7943ec99491acae1e55e1da46b39662e916085d5ed05
font_02_sfnt_off000121a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

Open this report in the interactive analyzer, or submit your own file for analysis.