Malicious PDF — malware analysis report

Static analysis result for SHA-256 37b18df0fbc23094…

MALICIOUS

PDF

71.6 KB Created: 2021-09-15 14:34:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c659039d24a6e6be5d32213ca7d6a17e SHA-1: d9a67537bf1ad018004a716c1df03743fa8c1a15 SHA-256: 37b18df0fbc2309453206b31289f9f8fdecefa50cea0d5079fee86e1ab1cf500
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. The embedded URLs, such as 'https://oniceh.ru/uplcv?utm_term=maths+text+book+class+11', are likely part of this redirection chain.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://oniceh.ru/uplcv?utm_term=maths+text+book+class+11 PDF link annotation
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/8sau21q3v60a9o6gf95f16vev7/67003929280.pdfIn PDF document text
    • https://monographie.com/ckfinder/userfiles/files/6934220122.pdfIn PDF document text
    • http://naphogacomposite.com/upload/files/61783874466.pdfIn PDF document text
    • http://www.videobezopasnost.ru/ckfinder/userfiles/files/71722541294.pdfIn PDF document text
    • http://architettorobertafasola.eu/userfiles/files/tulelarap.pdfIn PDF document text
    • http://cabinet-blin.fr/ressource/site-image/files/pebax.pdfIn PDF document text
    • http://birdwatching.sk/media/file/11819420111.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139e3f32b395---sewiluxujutigujik.pdfIn PDF document text
    • http://jnmindia.com/outscapes/admin/ckeditor/uploads/ck/files/13196944057.pdfIn PDF document text
    • http://fred-robin.com/ckfinder/userfiles/files/98462754437.pdfIn PDF document text
    • http://vhz.cz/user-files/30490029208.pdfIn PDF document text
    • http://halaljones.com/uploads/files/zolazafapenasinasex.pdfIn PDF document text
    • http://ylpqzl.com/ckfinder/userfiles/files/lavab.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16138627042162---tojatuxeditesufu.pdfIn PDF document text
    • https://hopefor.today/wp-content/plugins/super-forms/uploads/php/files/6f0b8bf04320dec25b01ec492cae5b1b/54993412296.pdfIn PDF document text
    • http://quocteanviet.com/img-chamthi/files/60119743385.pdfIn PDF document text
    • http://indago-rovigo.it/userfiles/files/86281412508.pdfIn PDF document text
    • http://www.prakashirrigation.com/uploads/fck/files/37062636828.pdfIn PDF document text
    • http://taispacedesign.com/upload/files/gevonatexevuxekajenagu.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/mixupanutupalewigiba.pdfIn PDF document text
    • http://studioriggio.it/userfiles/files/fovubejef.pdfIn PDF document text
    • https://pr-dienst.ch/file/27993435480.pdfIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/03164c004900373d69126caca30e9123/15696943819.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_off0000b6a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6A3 10408 bytes
SHA-256: a34a10de41d5de05b420d268747cc559a5ed70c3a362f4c178602b15c65424f5
font_01_sfnt_off0000ce77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE77 16084 bytes
SHA-256: f78cbec549fdfa8ae14ef1c2abd32767c147aff79932abedabd548afed1a5c0d
font_02_sfnt_off0000f7da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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