Malicious PDF — malware analysis report

Static analysis result for SHA-256 75aa75bc92e603ea…

MALICIOUS

PDF

74.3 KB Created: 2021-06-09 21:49:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 5f356962577bd91297295e497ee40793 SHA-1: 905770238e57844f8a2085ca755ff66316b47ec4 SHA-256: 75aa75bc92e603ea1836a89b423f9bc95cfbe2ad900c274778f98cec9f9657f6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains a link farm pointing to multiple compromised WordPress sites, likely serving as a distribution point for further malicious content. The document body, though heavily obfuscated, suggests a lure related to "multithreading java questions" to entice users to click the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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=multithreading+java+questions PDF link annotation
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1607a895f84f69---56238730751.pdfIn PDF document text
    • https://k2salight.com/wp-content/plugins/super-forms/uploads/php/files/6a38141cec1c319fa1106dbe499f37f5/nejukojawuzavamez.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/16098bb410f00a---kajapiga.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609d0c4cac463---bezedijiwurinujebisex.pdfIn PDF document text
    • https://ethiquedevelopers.com/wp-content/plugins/super-forms/uploads/php/files/dfa05e7554d4ad3914524ebd6b0d4522/kuparelofiguvaja.pdfIn PDF document text
    • http://middlegeorgiacoinclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d56142a24b---nabilujud.pdfIn PDF document text
    • http://alhouti.com/userfiles/file/59701845072.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16084bdaf1d3ba---59232070245.pdfIn PDF document text
    • http://pnmanagementsolutions.in/uploads/tewikovavenerajegonapo.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/fe6dfca305a9e22db5b3acccbabd9709/fakamewopobosixadef.pdfIn PDF document text
    • https://anfauglir.com/images/file/jatamisinuvutaleluji.pdfIn PDF document text
    • https://securitegenerale.tn/userfiles/file/85984110492.pdfIn PDF document text
    • http://okmarin.ru/userfiles/file/xufidapopa.pdfIn PDF document text
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/105a4f55e761dd5e76b227b66569485b/bimisiranapufaterosamupa.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e64b37ea7c---xazubatejefavaz.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/4r1ckb9n8oreitc8i7v9o50ps2/67507678282.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e3af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3AF 5356 bytes
SHA-256: 23bcc3fd77e2a6f04bb984dd54061b908d985bc08c7b1583688bcc385a9fd73d
font_01_sfnt_off0000f5e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5E8 11352 bytes
SHA-256: 85c65927c20a2d3f8636edeb78eec5dcecec93f3957dd498049f9800149a2039