Malicious PDF — malware analysis report

Static analysis result for SHA-256 658281d4d8091cc7…

MALICIOUS

PDF

95.7 KB Created: 2021-03-18 20:59:42 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 9e6adda3516cd1738d66ea538eb5ec4f SHA-1: 1f8b6524e2767f55ec62f750737d3775925ac961 SHA-256: 658281d4d8091cc7c0fa1823e42c822965e65cbb324de7dbcc996f4c1453fec0
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 of which are on disposable hosting, suggesting a link farm or phishing attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were extracted, the PDF structure and embedded URLs point towards a tactic of directing users to potentially malicious external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://jacksth.ru/strik?utm_term=who%2527s+afraid+of+virginia+woolf+george+character+analysis PDF link annotation
    • https://cdn.sqhk.co/tivanosox/hdhejgW/matomekigij.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405430/normal_6035cedc19482.pdfIn PDF document text
    • https://cdn.sqhk.co/numavagoko/pig27eG/simsimi_app_download_for_android.pdfIn PDF document text
    • https://cdn.sqhk.co/kevejonob/2p0ghjb/18425709131.pdfIn PDF document text
    • https://cdn.sqhk.co/nolagutotato/jaKjhij/xapanuwusapukizepe.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413119/normal_60386f8ab317c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408871/normal_6017df493d764.pdfIn PDF document text
    • https://cdn.sqhk.co/wopidevepip/x6ijPF5/batodibenoxuxo.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485308/normal_60293cdf7cb99.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366031/normal_6052662b148bf.pdfIn PDF document text
    • https://cdn.sqhk.co/lotuxuduvoki/j7xhbFa/ronejiwepipoju.pdfIn PDF document text
    • https://cdn.sqhk.co/widafopaj/KgdnAqx/duwomojoremot.pdfIn PDF document text
    • https://cdn.sqhk.co/gatidixon/fggiCfk/65597471748.pdfIn PDF document text
    • https://cdn.sqhk.co/zotenejek/jhZLiju/switch_to_t_mobile_deals_iphone_11.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/ac727cd0-4af1-4306-9339-9d89febe07d8/gigivadoviburivujidore.pdfIn PDF document text
    • https://7f993087-45f6-41f4-96e5-9dcaca18fb91.filesusr.com/ugd/9a92dd_5f4aae3fc1804a6b95c4e8585c3464bb.pdf?index=trueIn PDF document text
    • https://d45380bd-a93d-4ef2-b2bd-4c7806d1f6db.filesusr.com/ugd/5d2cf3_c7f5f26411c84495972ed5249560b1e2.pdf?index=trueIn PDF document text
    • https://c01188fd-d8af-4b86-846b-090f7ecd58d8.filesusr.com/ugd/9058e5_f3fd953ab0ad48d0a988e83b45121663.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/8b485c6e-bdcc-446b-a11d-de293c2c2656/how_to_change_wallpaper_on_amazon_fire_tablet.pdfIn PDF document text
    • https://beea745c-e446-4317-9ad8-fe501d584c0a.filesusr.com/ugd/9196db_c4c0e9a6981e4e6ea0aebcf10d40dc46.pdf?index=trueIn PDF document text
    • https://5e1449e8-5ae4-4a15-bc7a-ee23795bc964.filesusr.com/ugd/3a34a5_3cb993f05db9454497e256fa14579b8f.pdf?index=trueIn PDF document text
    • https://9ebe8999-295a-4f11-87dc-c96f3e1b46ff.filesusr.com/ugd/8de238_2e32de51eaad4172bb4e5885254a2c85.pdf?index=trueIn PDF document text
    • https://b1706aec-e9b1-4c6c-9a93-f14ef4a1c402.filesusr.com/ugd/3b47cb_3e97357873a64add903f3026c81fff5a.pdf?index=trueIn 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_off00013916.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13916 5584 bytes
SHA-256: e8e6c152bfa83420766249ec1d2ed897767331683e225ae9a17428c74c2bffb2
font_01_sfnt_off00014c3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14C3E 10696 bytes
SHA-256: ef5dfc890f28796826503aa9781a5119ba6ecf6ceddc1238bda5e33b5d3ac33c