Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc255b8cf9c6fd1a…

MALICIOUS

PDF

78.4 KB Created: 2021-04-16 20:24:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: a1e7b30b1bd3133e65be3b596e6a1fb4 SHA-1: b638732b4c79f526c645a1fdef07e19b5c3de27f SHA-256: dc255b8cf9c6fd1a281feb34891cfe0bcd463db28da5b21790897b121d419584
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of external links, many pointing to disposable hosting, indicating a link farm or phishing attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The embedded URLs are likely used to redirect users to malicious sites, potentially for credential harvesting or malware distribution.

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://druttle.ru/strik?utm_term=cubic+spline+end+conditions PDF link annotation
    • http://pet-guru.shop/kipejamufavonauj77x.pdfIn PDF document text
    • http://jarisudowapebi.sportsontheweb.net/50003803912.pdfIn PDF document text
    • http://mosomupusafebin.medianewsonline.com/cpa_2020.pdfIn PDF document text
    • http://nosinoski.shop/sofewumezagadelipijugs08g.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://981168d4-05fc-44b6-871d-73371d7e8cf1.filesusr.com/ugd/87d215_f4d817be0e414b1fbfdd264e2369f324.pdf?index=trueIn PDF document text
    • https://562a32fb-e9c8-4d8f-ac7e-a760da58c396.filesusr.com/ugd/68ec97_c3cefc9457604759afd8dc96e5384936.pdf?index=trueIn PDF document text
    • https://661c91a2-68a2-4ae3-aaac-ef96b6cc7894.filesusr.com/ugd/b926a8_b7846c888ba946be81208898e55a2b3f.pdf?index=trueIn PDF document text
    • https://8641c524-1fb5-4292-87ed-dd72f64d6c22.filesusr.com/ugd/9b7d8a_29af92c764b640d299a3d10b5d7cf2c6.pdf?index=trueIn PDF document text
    • https://76f5a3e5-08d8-4581-9975-6c1b933a1845.filesusr.com/ugd/dbbd16_511b20efbef34cb6a72f18f7b8f93a82.pdf?index=trueIn PDF document text
    • https://c1e70603-6ca1-47bc-880b-b60d7d434995.filesusr.com/ugd/df625d_08e9c871256a47019c2db94a1cb1f05b.pdf?index=trueIn PDF document text
    • https://8eccd3b7-fb20-4588-a5b5-4d8c58591879.filesusr.com/ugd/0e6328_8d89769fb4914665ba30caa3d212ef8a.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/gimufesajo/97932357596.pdfIn PDF document text
    • https://e0220c8c-c322-4c33-af83-7c5b0fe00b66.filesusr.com/ugd/a771bd_50f7653dfc6b4fa898e77cdc4de71fe8.pdf?index=trueIn PDF document text
    • https://76df98a8-3e94-4eee-a6f5-23e1de06049b.filesusr.com/ugd/54c74c_c43d66afccc24362a939d6ea3de8b359.pdf?index=trueIn PDF document text
    • https://73e8eba8-f08a-4c12-987a-519a82e171c2.filesusr.com/ugd/19159f_d2181a59e0f64c018e83d5743be329e8.pdf?index=trueIn PDF document text
    • https://b962d5b8-8819-42e3-9ba3-d95e8366760e.filesusr.com/ugd/f51585_deb0bd3e086f45aa84d2b1c0d908ed54.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/fejififimaketo/best_40_inch_4k_tv_reddit.pdfIn PDF document text
    • http://jopubijako.atwebpages.com/sutezede.pdfIn PDF document text
    • https://s3.amazonaws.com/farokof/9671783110.pdfIn PDF document text
    • https://c8070bf9-ed42-4c5d-8eb8-ca35ee70f136.filesusr.com/ugd/d38238_43e7693171aa4ad6b424b44eeec071f4.pdf?index=trueIn PDF document text
    • https://44bb6ee8-a0fe-4f72-890f-0f0a2fec05cf.filesusr.com/ugd/b65acf_c5ec8fbec65c4710989dfe9d3514fd9f.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/sowewazulejewi/crest_bronze_award_student_guide.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_off0000f457.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF457 4804 bytes
SHA-256: d75a9377c346c0a18aa06c3408901ce33e3b27f3c2e98051b84bde57f455c7e5
font_01_sfnt_off000104b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104B7 11492 bytes
SHA-256: 0f589757d48ac7cc500ac704c86257cef06ecb33c203ec54bd83bd57d004856c