Malicious PDF — malware analysis report

Static analysis result for SHA-256 839d889d9efc4e70…

MALICIOUS

PDF

62.8 KB Created: 2021-02-16 03:43:07 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ae83752f880cb07cb924c81c89419e36 SHA-1: 499c3b71e27d147787efffe600a4a570ad0663f3 SHA-256: 839d889d9efc4e702803b799255535adfb5c8e18fbc2cddbc1d84ca514e1486c
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, identified by the PDF_SEO_LINK_FARM heuristic, suggesting a link farm or redirection scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and numerous external URLs point towards an attack pattern involving user redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://maypoin.ru/wix?keyword=70-410+lab+manual+pdf
    • https://cdn.sqhk.co/tudobele/jfjgQea/nostalgia_meaning_for_dummies.pdf
    • https://rarejiwu.weebly.com/uploads/1/3/1/6/131606055/zivizuv_vuruvokujem.pdf
    • https://cdn.sqhk.co/telapunojawu/hNgijbD/89137225429.pdf
    • https://cdn.sqhk.co/xexisini/jbwP3ig/tinudakovul.pdf
    • https://cdn.sqhk.co/terasovo/BcgcjdB/62865784984.pdf
    • https://cdn-cms.f-static.net/uploads/4373797/normal_5fd8126c09486.pdf
    • https://cdn.sqhk.co/gulanuwe/f7ihXge/sexotisozise.pdf
    • https://cdn-cms.f-static.net/uploads/4369912/normal_60172a05e7839.pdf
    • https://cdn.sqhk.co/vefomatakin/hgidiiS/sibupulupoxopav.pdf
    • https://zozolexiwu.weebly.com/uploads/1/3/4/3/134343356/vorifelagobida.pdf
    • https://cdn-cms.f-static.net/uploads/4427105/normal_5fdae1ffb761e.pdf
    • https://lobekopaxukibo.weebly.com/uploads/1/3/1/4/131453735/1471307.pdf
    • https://kozewililusu.weebly.com/uploads/1/3/4/0/134013002/9038830.pdf
    • https://static.s123-cdn-static.com/uploads/4479904/normal_5ff30ea6aea43.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://jajoxutevo.epizy.com/uniden_bearcat_bc148xlt_scanner_manual.pdf
    • http://vedelobezab.rf.gd/ibps_rrb_admit_card_date_2018.pdf
    • http://navefifidarep.epizy.com/51026493431.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bab2.bin
143876c66c306e261f4d515f19b0414683eda679352abea485b361d9be7db659
pdf-font-stream PDF embedded font (sfnt) at offset 0xBAB2 5352 bytes
font_01_sfnt_off0000cce8.bin
120841a663f4ee987f8d5fb824658b7ccaaa2fc124f4d446e057cf90b759f96c
pdf-font-stream PDF embedded font (sfnt) at offset 0xCCE8 9820 bytes