Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5e7a304c8bc6b8f…

MALICIOUS

PDF

76.5 KB Created: 2021-06-02 06:57:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 37e8b9d841b8ff9f0d093e57ec25c9f4 SHA-1: 6af5b1586ecc95562ec54106cb275b17c8c20d69 SHA-256: a5e7a304c8bc6b8fde736298fb6f87c99fac3a10ff12cf660961211a1728fbb6
126 Risk Score

Malware Insights

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

The PDF document was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs, many pointing to disposable hosting, and is identified as a link farm. The primary malicious URL is https://midufefew.ru/123?utm_term=after_action+rails+format, which is likely used to redirect users to a phishing or malware distribution site. No scripts were extracted, but the PDF structure and URL analysis strongly indicate a phishing or credential harvesting attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 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://midufefew.ru/123?utm_term=after_action+rails+format PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4401703/normal_5ff16cb9c501a.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4381997/normal_60b6f2c970831.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4475716/normal_5ff50bb2d1475.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4500183/normal_5ffe4242d05b3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375071/normal_5fcd30af8e2e8.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4456982/normal_60b513fb7a2e5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417212/normal_602184bda9227.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4392666/normal_5fe2e799bbef8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464330/normal_60636c1353c98.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426267/normal_60571d4ea739e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413126/normal_6058a5b81259e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485004/normal_606274026f687.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4479904/normal_60b29b7b2cd77.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405440/normal_600e623806eab.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408987/normal_5fd36ce7cf7fd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376601/normal_603199f4c04d1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368221/normal_5fd650118e149.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409621/normal_605340247778a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417403/normal_5fdb0d9675ba1.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://veniwusuj.pbworks.com/f/driving_games_unblocked_google_sites.pdfIn PDF document text
    • http://mefijunov.pbworks.com/w/file/fetch/144416883/music_notation_ks2_worksheet.pdfIn PDF document text
    • http://tisowowuduwe.pbworks.com/f/qumica_fsica_atkins_8_edicin_descargar.pdfIn PDF document text
    • http://rujuboxu.pbworks.com/w/file/fetch/144477399/58775573169.pdfIn PDF document text
    • http://xuruzinijub.pbworks.com/f/lolozatojopanirapitanar.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_off0000ecf0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECF0 5048 bytes
SHA-256: f8e39c2e6313794ee54be6735d3abb557f3af98f3ecc13b7228beb61b3ba5fe7
font_01_sfnt_off0000fe0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE0F 11208 bytes
SHA-256: 60dc8a407fc675d0558624b315ce574c9f0d2d5ce14bf1ec62a116783c2e069b