Malicious PDF — malware analysis report

Static analysis result for SHA-256 41e0128e753111c4…

MALICIOUS

PDF

70.1 KB Created: 2020-12-14 21:02:12 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: ec04fa4dcd6d5116f79bdef3d414e48a SHA-1: 9516d2d1491c39edf500112c585a7d155d6dfe2c SHA-256: 41e0128e753111c40377aa472b7b092ff1aaaaca504c5b4fa43bab4ba70c62f4
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which are SEO-like, suggesting a link farm or phishing attempt. ClamAV and ML classifiers also flagged this PDF as malicious, specifically as a phishing trojan. The document body, though heavily obfuscated, appears to be a lure related to GRE physics practice questions, aiming to trick users into visiting malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://trafficel.ru/123?utm_term=gre+physics+practice+questions+with+explanations+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4409421/normal_5fad314187879.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366009/normal_5f98dcd87d5b2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4504922/normal_5fad77cdcbca3.pdfIn PDF document text
    • https://zisokilusativ.weebly.com/uploads/1/3/2/3/132303079/madovisuzudoni-jijijaji-ladovetalota.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/mijedusovineti/80540633112.pdfIn PDF document text
    • https://s3.amazonaws.com/vovopafubipu/funky_town_lucky_chops_sheet_music.pdfIn PDF document text
    • https://s3.amazonaws.com/musoxifuvitalo/create_new_sheet_in_excel_vba_macro.pdfIn PDF document text
    • https://s3.amazonaws.com/viromibukoleliw/tugugun.pdfIn PDF document text
    • https://s3.amazonaws.com/zoromexemuzid/tes_spanish_comparatives_worksheet.pdfIn PDF document text
    • https://s3.amazonaws.com/jiwotarotavuz/lasuxerotisatetudix.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d438.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD438 5660 bytes
SHA-256: 3652651692beeca7915685870d637f3ed9fb2c112a53b8bf23a362acb84ce5d4
font_01_sfnt_off0000e793.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE793 10596 bytes
SHA-256: 369d599c542ececc13d97cb725ffe28243b0c9fc2ebd8e30d45bcd5821235927