Malicious PDF — malware analysis report

Static analysis result for SHA-256 6138535a4454ce73…

MALICIOUS

PDF

74.8 KB Created: 2021-09-13 15:17:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 162542f9ba8f56f0024c6927a6d00777 SHA-1: d29e7c99fe2aa3de83a5c31a6aa204f98ae292e6 SHA-256: 6138535a4454ce736b2c38b6d6b0b388eb6bf033c404f02f5a168a86fe795ec2
126 Risk Score

Malware Insights

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

The file was identified as malicious by a ML classifier and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to disposable domains, suggesting a link farm or phishing lure. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior, indicating the PDF is designed to redirect users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://citra.cl/userfiles/file/36172505090.pdf In PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/16134fd5804916---dedugexuwov.pdfIn PDF document text
    • https://raguvosbaldai.manovonia.lt/images/files/92728680309.pdfIn PDF document text
    • https://valenciamaids.com/userfiles/files/bogitepali.pdfIn PDF document text
    • http://art-wonders.com/ckeditor/ckfinder/core/connector/php/uploads/files/jedatikijubiwaro.pdfIn PDF document text
    • http://digitalpolicycouncil.org/imagenes/file/zikekafij.pdfIn PDF document text
    • http://dralituncer.net/userfiles/file/vidaxepiv.pdfIn PDF document text
    • http://haki.vn/uploads/files/21405218039.pdfIn PDF document text
    • https://eliteplacementagency.com/uploads/files/66550144745.pdfIn PDF document text
    • http://jfhcoaching.nl/userfiles/files/5821277709.pdfIn PDF document text
    • https://altaamir.ipixpms.com/Rapport/public/assets/ckfinder/userfiles/files/94340912892.pdfIn PDF document text
    • http://iknow.pl/files/file/37623110125.pdfIn PDF document text
    • https://hattshopping.com/admin/assets/images/ckfiles/63250506316.pdfIn PDF document text
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/35a0f98b5d254741c2c8b897a7271ac7/41828180383.pdfIn PDF document text
    • https://warungmimpishio.com/contents/files/78334693482.pdfIn PDF document text
    • https://carrieres-pierre.com/userfiles/file/fibevijolapopodulejes.pdfIn PDF document text
    • http://wasserentkalkung.at/ckfinder/userfiles/files/nukovajemebuxevanesi.pdfIn PDF document text
    • http://hijoin.hu/editor_up/revogenexibirukuwulekotu.pdfIn PDF document text
    • https://singlespeed-switzerland.ch/userfiles/files/faraliz.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/161342da2c5fc8---36173463339.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=save+hero+goalkeeper+apkPDF 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_off0000c1d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1D2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d9e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9E9 10300 bytes
SHA-256: 1535065945ff4ef558a131091b4bec6a26fc499bdeb7e45116f9f7eef93ff138
font_02_sfnt_off0000f149.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF149 17152 bytes
SHA-256: 550894853453367b1ac092d1938f2a5a162743caaa7e750e187ed4c0cd4ae0af