Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf7f71d9bf1ae8c1…

MALICIOUS

PDF

77.3 KB Created: 2021-03-11 18:57:41 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 5cff86f0fc2bb91d023b0b1e63fa1b44 SHA-1: 5f80b0b7778540132f4de6e91a43c64a6de0721d SHA-256: bf7f71d9bf1ae8c1e361ad8000db6234f8daaaf1116a0827ca5c7741c2a70a91
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO spamming operation. The primary URL, https://nipisod.ru/award?keyword=1000+books+you+must+read+before+you+die+pdf, is likely part of this scheme. ClamAV and ML classifiers also flagged this PDF as malicious, indicating a phishing or trojan distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nipisod.ru/award?keyword=1000+books+you+must+read+before+you+die+pdf PDF link annotation
    • http://lalabomujulimof.mywebcommunity.org/xoduveduvukokela.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460980/normal_6016078072e1e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450034/normal_601bdd5937d02.pdfIn PDF document text
    • http://devuweza.scienceontheweb.net/giwapawonavarexexikef.pdfIn PDF document text
    • http://buwubaled.mywebcommunity.org/pojilozi.pdfIn PDF document text
    • http://gejedesoni.getenjoyment.net/zudofumufosatenutil.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://c93e3e17-565c-496b-95a0-45fea83b015f.filesusr.com/ugd/cd9bb8_59a677c85f004608a4adb794a5d84eb8.pdf?index=trueIn PDF document text
    • https://5bf49506-6ef1-42f8-8f90-7e3689255fd3.filesusr.com/ugd/8fe1bf_0fb1e825c05a488ea605616fa7081d4c.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/f2b82fc7-aebe-45b0-85fc-51adc7e68f58/jinenap.pdfIn PDF document text
    • https://7f03322d-63d6-449b-a8c2-a80beffeb2b6.filesusr.com/ugd/2994dd_4e5c6723843847eebabe6ce379ed99b4.pdf?index=trueIn PDF document text
    • https://2987c0f4-171e-4473-b3f1-a5468658115b.filesusr.com/ugd/75ff8a_3135cab8a7904b758a053d09457f6673.pdf?index=trueIn PDF document text
    • https://52ed6390-a5c1-4502-9f93-599cf6d98ad1.filesusr.com/ugd/f7fbc8_e1f1d4d939cc428a829be0fb870d7377.pdf?index=trueIn PDF document text
    • https://e5b7f393-9b83-42c5-a877-5b85c0c772c8.filesusr.com/ugd/77b42d_1387620279454e5a9697dc6297bc2c92.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/7577fcb3-79df-4d75-896a-78aeb8459e1b/the_crown_season_3_episode_4_cast.pdfIn PDF document text
    • https://s3.amazonaws.com/bofake/pixezo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e42431ee-59a7-4964-80c0-235ca75e426d/how_to_find_your_chinese_zodiac_sign_compatibility.pdfIn PDF document text
    • https://f50ece36-1901-4a7b-9396-968a400df7f4.filesusr.com/ugd/3ecb95_9eeb10072a81490ab1e771acaa29386f.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/ritoma/loruk.pdfIn PDF document text
    • https://7afd96e6-4611-46d4-9b98-d111b897c281.filesusr.com/ugd/154221_897661e2381e4c35b712d2a0e6a665d4.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_off0000f147.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF147 5560 bytes
SHA-256: 8e524e7c53a387fdb686bc0936c09b760961acf4df3015b95f91ea0806f5a2ef
font_01_sfnt_off00010421.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10421 10376 bytes
SHA-256: c8cd2f96b8b8d1ddec530f78e15dbdd5f4647a016e72ea34bbf0298de0d9feee