Malicious PDF — malware analysis report

Static analysis result for SHA-256 a2764fb8551bb5e0…

MALICIOUS

PDF

39.9 KB Created: 2020-09-30 16:59:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 4652a90a4f19b29ba201d518c51ed15c SHA-1: 74c06e0039e359232d9ba04f2db4bee1a48bd5f4 SHA-256: a2764fb8551bb5e09795bed29b0443b5161cd1fdb5d0aa66f444bc908d892abe
192 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many pointing to external PDF files hosted on various domains, suggesting a link farm or redirection scheme. One of the URLs, 'https://cctraff.ru/strik?keyword=webarchive+to+pdf+pc', is flagged as a known malicious redirector. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, contains similar URLs, reinforcing the finding of a link farm designed to lead users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 6

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://cctraff.ru/strik?keyword=webarchive+to+pdf+pc In PDF document text
    • http://files.albertfpark.com/uploads/1/3/0/8/130813770/3003155.pdfIn PDF document text
    • http://maruzobog.fusedfinery.com/uploads/1/3/0/8/130874276/178838.pdfIn PDF document text
    • http://giredov.ladysweetcakes.com/uploads/1/3/1/3/131383483/vunokun_tovutife_meramotitiwe.pdfIn PDF document text
    • http://files.suewilliamsart.net/uploads/1/3/0/7/130775076/493089.pdfIn PDF document text
    • http://files.cupcakekisses.org/uploads/1/3/1/3/131398109/3106751.pdfIn PDF document text
    • http://jemazozan.travelvideofi.com/uploads/1/3/1/1/131164159/rukifuzidi_jutufakevilen_gumobanavafovop.pdfIn PDF document text
    • http://bupadof.softcinch.com/uploads/1/3/1/3/131380504/dd7776096a0e34b.pdfIn PDF document text
    • http://zaboji.wallowhollowfarm.com/uploads/1/3/1/8/131871710/dugemafi_ragixi.pdfIn PDF document text
    • https://site-1037141.mozfiles.com/files/1037141/12835485388.pdfIn PDF document text
    • https://site-1037182.mozfiles.com/files/1037182/49125393045.pdfIn PDF document text
    • https://site-1036734.mozfiles.com/files/1036734/nutiloteriwinapomud.pdfIn PDF document text
    • https://site-1036724.mozfiles.com/files/1036724/mefabaganu.pdfIn PDF document text
    • http://pevazibin.lcandlepress.com/uploads/1/3/0/7/130776082/deserivum-vajikijirixa.pdfIn PDF document text
    • http://files.barneysbergdorfsbills.com/uploads/1/3/0/7/130738753/998962a6d3bd.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off00005e2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5E2F 5244 bytes
SHA-256: 7786158dee2052f3f11d341fa7fb8e32d5a399b890412198d64ba575e081f110
font_01_sfnt_off0000700e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x700E 10192 bytes
SHA-256: c897c8f12b7881442b576e47901ff4867440c5f0a167c41966425cc209fdb4a7