Malicious PDF — malware analysis report

Static analysis result for SHA-256 55d1a26b3eab5b40…

MALICIOUS

PDF

81.4 KB Created: 2021-03-17 22:46:02 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: c1a1c29d4885449c22f27ae99aafe934 SHA-1: a86d01d1cc6760b2364af1b1f6f7a6169f1f72bb SHA-256: 55d1a26b3eab5b40478600ac2cf6b2ea7140e05bfc683019f6b19aae38b94a64
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm likely used for SEO manipulation or to distribute further malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, with the PDF_SEO_LINK_FARM heuristic confirming the suspicious link structure. No scripts were extracted, but the presence of numerous external URLs points to a phishing or content distribution attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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.
  • 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://seumenha.ru/wix?keyword=airsoft+boneyard+m4 PDF link annotation
    • http://xatasawijuli.22web.org/business_communication_notes_for_mba_free_download.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413987/normal_5ffba343b2da9.pdfIn PDF document text
    • http://kogemotuju.getenjoyment.net/criminal_law_and_procedure_textbook.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405179/normal_600db406763e1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459929/normal_60279e43a6c16.pdfIn PDF document text
    • https://mejodedasebedo.weebly.com/uploads/1/3/4/7/134725949/2530492.pdfIn PDF document text
    • https://lezuzanufebaj.weebly.com/uploads/1/3/4/8/134873312/lafamibejipezi.pdfIn PDF document text
    • https://petekebinipaz.weebly.com/uploads/1/3/5/3/135395272/4580804.pdfIn PDF document text
    • http://folugomobok.getenjoyment.net/81382247527.pdfIn PDF document text
    • http://jorowijedo.mywebcommunity.org/15198131474.pdfIn PDF document text
    • http://duzusedolatepe.mypressonline.com/telugu_alphabets_chart_with_hindi.pdfIn PDF document text
    • https://lenukanaferu.weebly.com/uploads/1/3/0/8/130873899/0b16e9de337c.pdfIn PDF document text
    • https://bifukumuvu.weebly.com/uploads/1/3/5/3/135347201/9125641.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://puxujedupis.epizy.com/tovugipagotakabojukug.pdfIn PDF document text
    • http://vokunewegulu.epizy.com/ararara_marathi_song_free.pdfIn PDF document text
    • https://01c19f78-c7d0-441a-b56a-8672493f87de.filesusr.com/ugd/9d66c7_6b2a7a6174a94b8fb62487828beff8cc.pdf?index=trueIn PDF document text
    • https://5090c2af-253d-40c3-bfb7-942fc6db26b0.filesusr.com/ugd/0511f5_114357edab9e445ea3664891de362662.pdf?index=trueIn PDF document text
    • https://6c8027e1-9878-41b3-a9ef-32ba2b6bcd02.filesusr.com/ugd/185811_36d1f88a92344f3eb2ff1b98a42db167.pdf?index=trueIn PDF document text
    • https://cf62593c-3f62-494e-9ef9-3c2a63ead7d7.filesusr.com/ugd/93dae2_57b6ff86511b44d5aca6d0308cbb2cc8.pdf?index=trueIn PDF document text
    • https://945b3f91-9c76-4178-be32-f0dab3cfe2c6.filesusr.com/ugd/8d5d69_12f8eab84d914c578b48688c6af24ee3.pdf?index=trueIn 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_off000101b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101B0 5340 bytes
SHA-256: 9ea91c4922aa3a3e9303d2b4ab2f4713238c9af27115282e32ce2ea72574278e
font_01_sfnt_off000113cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113CC 10808 bytes
SHA-256: d5e8d86781d240d4e96fd4c34121c2dc22b1798e7a72cf28943bef8477f8c0c7