Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb60a425a5311e48…

MALICIOUS

PDF

76.0 KB Created: 2021-03-28 06:21:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: e146c0f6261ebab651e28c82db9a1d38 SHA-1: f4a4cd483d5f69ff149faf5e23f6071a69d93b3d SHA-256: cb60a425a5311e48e646e2b72e578cfce2aa36082c1fa97d0e2d9699e503be6b
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 hosted on disposable domains, indicating a link farm or SEO spam campaign. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to redirect users to phishing or malware sites. No scripts were extracted, but the PDF structure itself is used to facilitate the malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://kuzutuzo.ru/award?keyword=abdominal+ultrasound+step+by+step+3rd+edition+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4448110/normal_605986a496266.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4451544/normal_5fe5ad5a0e45a.pdfIn PDF document text
    • http://muriwilosakud.iblogger.org/steroidal_alkaloids.pdfIn PDF document text
    • http://nopipawipafa.22web.org/chilling_adventures_of_sabrina_book_1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4424991/normal_601fb198382ab.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419623/normal_600e8f0a1c3e9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480397/normal_601126239fd1e.pdfIn PDF document text
    • http://zalofamanaw.22web.org/gafom.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4419430/normal_5ff305aa5b36c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451018/normal_5fd86359b5b9f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4477626/normal_5fd3cc8cd4089.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413865/normal_6032fb9a09409.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://bogibil.rf.gd/how_to_rearrange_pages_in_using_adobe_reader.pdfIn PDF document text
    • https://8a7e94d2-1b07-4399-8a7b-cfebf1eb419e.filesusr.com/ugd/e78b77_7cee47c3dbe647038649042a0e19c854.pdf?index=trueIn PDF document text
    • https://7e079b21-6cfc-4bbc-a8af-001f4930a7f2.filesusr.com/ugd/f66805_46db733f6d1241d7bc7760b0ad672f06.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/baxekojojexusol/vagolotabidezizukutamoxaw.pdfIn PDF document text
    • https://4eb83289-b313-4542-b68c-79a1d4783db4.filesusr.com/ugd/f6336d_8c477eaee76e4365b7580e3c145fd2da.pdf?index=trueIn PDF document text
    • https://04934832-22f3-474e-96de-b9d593e92251.filesusr.com/ugd/f390e7_6b721812789c4ead82298de7a4800481.pdf?index=trueIn PDF document text
    • https://2e8e3215-33bf-4fe1-bc67-b38dac560527.filesusr.com/ugd/269bb8_11706d57bf9048ec8d7d29ff379b768b.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/dedinavesute/47326441986.pdfIn PDF document text
    • https://s3.amazonaws.com/xovekolamoxe/riferanob.pdfIn PDF document text
    • https://77a5c3e7-429a-4f60-ad30-886abaef4f6e.filesusr.com/ugd/07a1ab_4488200725bf44718cc97652b70695eb.pdf?index=trueIn PDF document text
    • http://sodanone.rf.gd/41985576864.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_off0000e98f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE98F 5580 bytes
SHA-256: 3de0eb5596e9aa14fbe102e787a4281a45052ced42530732b025c0ec01566e74
font_01_sfnt_off0000fc72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC72 11132 bytes
SHA-256: 2912777617f71050882b1057fce8079633af7c4a586da8935ede1567417dd1f5