Malicious PDF — malware analysis report

Static analysis result for SHA-256 2155b1fd94836f19…

MALICIOUS

PDF

74.0 KB Created: 2021-03-16 22:32:51 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 540f0b54742d3ba32578a7ad09211b84 SHA-1: 26fd49c1e6805018fb52cbc2c61e8d0f2ef8af29 SHA-256: 2155b1fd94836f1902e0f7d5757dff2c2f665d8c539e80f35a8c6e1baf892352
136 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and ML classifiers indicated a high probability of maliciousness. A heuristic identified an image lure linking to an SEO redirector, specifically the URL https://jacksth.ru/wix?keyword=accuracy+precision+and+error+worksheet+answers, which is likely used for phishing or malware distribution. No scripts were extracted, but the overall structure and URL suggest a phishing attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://jacksth.ru/wix?keyword=accuracy+precision+and+error+worksheet+answers PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4373526/normal_5fef998cb0156.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4495686/normal_5fec1321b3b38.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4495685/normal_5ff27543941ab.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370054/normal_604ecf7ee4269.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370780/normal_600ef930d5417.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375894/normal_602b90dd23c82.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4458412/normal_601dfcd08b319.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393631/normal_603353c3c92ca.pdfIn PDF document text
    • https://cdn.sqhk.co/jakufomego/hh8giD2/earth_3d_live_wallpaper_windows_10.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495841/normal_603ffe0f7235f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416319/normal_5fe93e114d05f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403262/normal_602efcbe188a8.pdfIn PDF document text
    • https://cdn.sqhk.co/fopalixogul/PjdCmPt/67467258128.pdfIn PDF document text
    • https://cdn.sqhk.co/gonolesuzam/hijiljb/tumblr_drawings_couples.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/24e7fd1f-b7a6-45f1-8cc9-0188fccc9eeb/mekikujuwaxebe.pdfIn PDF document text
    • https://s3.amazonaws.com/medaliwifufugel/south_park_fractured_yaoi_guide.pdfIn PDF document text
    • https://s3.amazonaws.com/solonebosop/purble_place_para_celular_android.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ab0fb885-165e-4244-87f6-9c77ec0fc3db/ideas_and_opinions_quotes.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_off0000e2a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2A4 5376 bytes
SHA-256: 24b2cec2dbd93f83b5b6103ebbbd861b1810660b775249020b5780dba2a6b760
font_01_sfnt_off0000f4ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4FF 11188 bytes
SHA-256: 3d9ca524138f88505688db472b1aa11d80ae370c4e85048037dfc2ff4d6acd2c

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