Malicious PDF — malware analysis report

Static analysis result for SHA-256 33f6757d8ac56b8a…

MALICIOUS

PDF

76.2 KB Created: 2021-04-05 07:11:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 5879d11ff214fbb7b3eda3c9747256c3 SHA-1: 6a29467a6860c88e29f8781a3e90191b91cf84d4 SHA-256: 33f6757d8ac56b8aa3578349fc511a1ea72ff15518e562829fa63bdbc326a07e
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 or SEO manipulation tactic. ClamAV and ML classifiers identified this PDF as malicious, specifically flagging it as a phishing or trojan. The presence of external URIs and the overall structure strongly suggest this document is intended to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://crophysi.ru/123?utm_term=manualidades+disfraces+halloween+para+ni%25C3%25B1os PDF link annotation
    • http://midumadataresut.66ghz.com/81893504656.pdfIn PDF document text
    • https://cdn.sqhk.co/vifamepupib/c1geuBQ/64441277839.pdfIn PDF document text
    • https://cdn.sqhk.co/tofatuxurejo/x3ibhNa/56686496139.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367941/normal_60565b5fd99c1.pdfIn PDF document text
    • https://cdn.sqhk.co/bodevoposuji/bL0jj6h/pull_the_pin_app.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412173/normal_5fe66b5a06bd3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4447658/normal_5fe2e889e5337.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4376874/normal_5ffbd73018da4.pdfIn PDF document text
    • http://nigoviwan.22web.org/vatakivoropifedilamok.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476002/normal_60571d2f17c6c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369310/normal_6025ab4021802.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415937/normal_5fda5fc6884e7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375341/normal_601a07233270f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403276/normal_606a3933778c2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420432/normal_5fe7bce2d5b71.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/8ce75506-ebb6-41ad-8d78-3390d059b6fa/work_self_assessment_essay_sample.pdfIn PDF document text
    • http://xugojejusovofeb.rf.gd/sosegasemiloluvebetelut.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/aacf5949-c20c-422f-8701-3a3d4045a1ca/absalom_absalom_chapter_2_summary.pdfIn PDF document text
    • http://nafuleleg.epizy.com/what_is_the_story_of_les_miserables_all_about.pdfIn PDF document text
    • https://d4a58959-25bc-41ae-a48c-99f47e3c4711.filesusr.com/ugd/4dab1e_4a94f7270d054f4c9f1da8423a05ef76.pdf?index=trueIn PDF document text
    • https://6e337ffa-6c75-4e98-916f-0cab85e7e3f5.filesusr.com/ugd/a22560_128bcc9cb816463a85b48bc2f05c4954.pdf?index=trueIn PDF document text
    • http://ximedamolaxeve.epizy.com/murejorudejazidu.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_off0000e89b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE89B 5552 bytes
SHA-256: 44806a9a151b7bee23ee18545552a26b319b95174167d7c4d3505283858a9c1b
font_01_sfnt_off0000fb56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB56 11580 bytes
SHA-256: bcc3f8a35e2b02b2f0eb7d66636f3340be7382c3a2e23767c522bd93f8dee55d