Malicious PDF — malware analysis report

Static analysis result for SHA-256 b33798622fc24d34…

MALICIOUS

PDF

101.1 KB Created: 2021-05-27 18:21:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: c7bf55299531fb34dadd95bc1dd335b8 SHA-1: e4f9a67996b8cc3292f72d2e040912864ed92ada SHA-256: b33798622fc24d34f14f05972c9d57b810bb0a722c7333d74b763860a784cfd6
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 pointing to disposable hosting services, suggesting a link farm or phishing operation. The ClamAV detection and ML classifier strongly indicate malicious intent. While no scripts were explicitly extracted, the presence of numerous external URLs and the nature of the heuristics suggest the document is designed to redirect users to malicious sites, potentially for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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/strik?utm_term=adding+and+subtracting+fractions+worksheets+5th+grade+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4383467/normal_601044229b830.pdfIn PDF document text
    • https://puxipevabama.weebly.com/uploads/1/3/4/3/134308905/bed03c48c7fa536.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4378164/normal_5ff9fc3b1f9cd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411701/normal_60190c2e616dc.pdfIn PDF document text
    • https://lenusasifelodu.weebly.com/uploads/1/3/4/3/134350773/72e4194231f522.pdfIn PDF document text
    • https://poliradu.weebly.com/uploads/1/3/5/9/135991332/lagefufumuzotisovi.pdfIn PDF document text
    • https://winetokazujubap.weebly.com/uploads/1/3/4/3/134321452/6852774.pdfIn PDF document text
    • https://nawamawivawugu.weebly.com/uploads/1/3/1/3/131398148/sesuve.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476270/normal_60175278816e8.pdfIn PDF document text
    • https://tofexozulemun.weebly.com/uploads/1/3/0/9/130969243/fadanemop_gemoweg_jaguvebomixogew_jatax.pdfIn PDF document text
    • https://jajibesuwazigix.weebly.com/uploads/1/3/1/3/131383486/4451688.pdfIn PDF document text
    • https://vusowosunuk.weebly.com/uploads/1/3/5/9/135975823/cf0a2d.pdfIn PDF document text
    • https://luzurojavozajin.weebly.com/uploads/1/3/6/0/136090511/kafip.pdfIn PDF document text
    • https://jopuwijexanubuf.weebly.com/uploads/1/3/0/8/130874501/zowilopuperot-dilowusepux.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/e34118b2-a304-4bd8-adb3-8956858d8461/skf_price_list_2021.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3f9adf42-355c-4af7-9247-effb58032d31/rijomenavofodaz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7391e1d9-2d2a-4ad1-866e-db820a7a4174/tusklessness_problem_or_solution_worksheet.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001384a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1384A 5792 bytes
SHA-256: 65cf2797160c179ab373f67ed978ed1744ae1053199473a902c67653323761f7
font_01_sfnt_off00014c1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14C1B 10544 bytes
SHA-256: 1305615565f6b7bd421589bdc486dfb86c33cee852075b4471ebb50b62b69e10
font_02_sfnt_off0001706c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1706C 16176 bytes
SHA-256: 8571c69df712043f52364268a050b27bc1059f3809e3f2b49cbb8768f33e3ff2