Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d7bffae507f7180…

MALICIOUS

PDF

76.0 KB Created: 2021-09-02 23:55:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 1777145a8b602854054860de73a091b9 SHA-1: 826e4d35bde72bf983dba7631acf936b20e0a9c8 SHA-256: 3d7bffae507f71804d8567539f580f44ab25a21a9ce2006e50148fe2f5e78e3b
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. Numerous heuristics point to the PDF acting as a link farm, directing users to compromised websites and potentially disposable hosting. The embedded URLs suggest a phishing or malware distribution scheme, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://nomylo.ru/uplcv?utm_term=prepositions+of+place+pdf+exercise PDF link annotation
    • http://bjhtdszdh.com/v15/Upload/file/20215191242224882.pdfIn PDF document text
    • https://hoakhanh.vn/uploads/image/files/fubodasirutumujeres.pdfIn PDF document text
    • http://csc-028.com/userfiles/file/20210806052913_2jtgjo.pdfIn PDF document text
    • http://wo-kop.pl/userfiles/file/86640121810.pdfIn PDF document text
    • http://cu-hinothai.com/ckfinder/userfiles/files/rivufakojifelojikij.pdfIn PDF document text
    • http://mskabel.cz/UserFiles/File/23932683165.pdfIn PDF document text
    • https://emauto.lv/index/images/up/file/dobikowoxepedevomuzudik.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/e563e7a2bf6c3a21d598468ac15c8f72/benifefiwotanutubisokezi.pdfIn PDF document text
    • https://khangle.vn/uploads/images/files/82707405381.pdfIn PDF document text
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/b0b487af3ddf1bb27eea19ddc5f06b53/nijexibizukewifolixoxewo.pdfIn PDF document text
    • http://sunnysidehighschoolclassof59.com/clients/867562/File/munered.pdfIn PDF document text
    • https://netiko.fr/img/Data/file/25530692443.pdfIn PDF document text
    • https://weddingitaly.jp/images/file/88784676001.pdfIn PDF document text
    • https://simplehome.ro/ckfinder/userfiles/files/kefutikafegagokikeb.pdfIn PDF document text
    • http://bhk-aindling.com/userfiles/files/gavosaniwisowevifav.pdfIn PDF document text
    • http://fresh-j.info/images/uploadedimages/file/80349943019.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/5b1d12445b00d58c2828bb2b75fda15f/banekuwilulawasaxe.pdfIn PDF document text
    • http://shahnawazonline.com/uploads/files/piwupapim.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160b25c9cc84f8---91362710083.pdfIn PDF document text
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/791mgucdj7rtnffsj9esjh9ju8/69463970515.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083417946f93---kavisoganunexasulinanabaz.pdfIn PDF document text
    • http://maasmartcity.com/userfiles/file/90435461742.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/161158c50db92d---fasiduzaxepigakuj.pdfIn PDF document text
    • http://seksdagen.nl/userfiles/file/pexorupikawoninalurirum.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/tawekodujabovigepo.pdfIn PDF document text
    • https://anakaygame.com/calisma2/files/uploads/81256941444.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_off0000c465.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC465 10716 bytes
SHA-256: 1f900b9dff74b90a6a0483b83b5737e639dcbbf31558aaad852e5384ee49dbcc
font_01_sfnt_off0000dd21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD21 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f533.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF533 17632 bytes
SHA-256: fe98b7c3221e12a42c05a413a24bb926037998bba4dea9a4027f1145034360d5