Malicious PDF — malware analysis report

Static analysis result for SHA-256 a98cdeb2cb75b8cd…

MALICIOUS

PDF

85.1 KB Created: 2021-09-09 17:27:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: a7cf2f7675c4ac9611b55611e8d6d9a0 SHA-1: 66a2e6f7c34793871dcdf958a5e7d45c022fcbe4 SHA-256: a98cdeb2cb75b8cd7e4b7557af1eb831be3d48b0180097904d4d54f0bc02aa06
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV also identified it as malicious, specifically a phishing trojan. The document body is heavily obfuscated and unreadable, but the presence of numerous external links strongly suggests a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://clarksville.net/wysiwygfiles/file/60354933694.pdf In PDF document text
    • https://aslimitada.com/userfiles/file/tituramimosokiligulis.pdfIn PDF document text
    • https://pamukoglu.com/userfiles/file/nonetope.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/cbb76d44ca821fb2d88604800bdce55e/5927894097.pdfIn PDF document text
    • http://briquettemachinery.com/d/files/43370836642.pdfIn PDF document text
    • http://kondicionery-lobnya.ru/upload_picture/file/20881918789.pdfIn PDF document text
    • https://alasclub.gr/neuro/ckfinder/userfiles/files/pajim.pdfIn PDF document text
    • http://mbjarrahi.com/UploadedFiles/New/file/82778906513.pdfIn PDF document text
    • http://kraski-chernila.ru/resources/file/bakubosomuxaru.pdfIn PDF document text
    • http://klick-tipp.info/ckfinder/userfiles/publics/files/beradave.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///53794839631.pdfIn PDF document text
    • https://tectrongim.com/uploads/file/72945952427.pdfIn PDF document text
    • https://rockyhotelsgroup.com/uploaded/files/88756577896.pdfIn PDF document text
    • http://szmchem.com/userfiles/file/55434133834.pdfIn PDF document text
    • http://dermalab.pl/userfiles/file/14580390959.pdfIn PDF document text
    • https://uzsienis.cvzona.lt/resources/img/files/donovux.pdfIn PDF document text
    • https://athensviptour.com/wp-content/plugins/super-forms/uploads/php/files/dbd0230f48177fb31bc1f82ef231e098/12331707872.pdfIn PDF document text
    • https://takipbizde.com/calisma2/files/uploads/nifemo.pdfIn PDF document text
    • http://nincity.de/inline/file/85848931265.pdfIn PDF document text
    • http://minhtoangalaxyhotel.vn/app/webroot/files/ckfinder/files/guxonetaxurusokemadani.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613192fd7b4ea---bidusonaraxax.pdfIn PDF document text
    • http://fishtech.org/uploads/userfiles/file/file/lojif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=how+to+get+the+luger+in+payday+2PDF 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_off0000e312.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE312 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fb29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB29 10912 bytes
SHA-256: 9285912f5e667cae172dd7648120d34186a73680f118ee153e7eca1f6f29284d
font_02_sfnt_off00011432.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11432 19644 bytes
SHA-256: 40038f7ffb3b0ce70e7145c4a085bc18e368958daf8ddd2733083aefd15f31f4