Malicious PDF — malware analysis report

Static analysis result for SHA-256 65d7f21dfb9fd88a…

MALICIOUS

PDF

80.0 KB Created: 2021-06-01 15:53:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 9b20eae2747d3512038d02ac6690f75d SHA-1: bc68c2f76a1fb813be5da1005785a124f71e291e SHA-256: 65d7f21dfb9fd88a82ac969bd5dd83727c23af292747a3178c841eddf5e4668d
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics, including ClamAV and an ML classifier, as malicious. It contains a large number of external links, many of which point to PDF files, suggesting a link farm or SEO spam operation. One of the embedded URIs, 'https://infrive.ru/pbw?utm_term=what+are+the+different+types+of+charts+in+ms+excel', is likely part of a phishing or scam campaign designed to drive traffic to malicious sites. No scripts were extracted, but the PDF structure itself is indicative of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://infrive.ru/pbw?utm_term=what+are+the+different+types+of+charts+in+ms+excel
    • https://static.s123-cdn-static.com/uploads/4426556/normal_60088bcfd92dc.pdf
    • https://static.s123-cdn-static.com/uploads/4499636/normal_600864a75224d.pdf
    • https://zitidifomeki.weebly.com/uploads/1/3/1/4/131412181/pedisedimisu-xoguzoxafi.pdf
    • https://wadaletabuj.weebly.com/uploads/1/3/2/6/132695896/5191135.pdf
    • https://cdn-cms.f-static.net/uploads/4393197/normal_6042c57032c74.pdf
    • https://mozufutedubido.weebly.com/uploads/1/3/4/5/134503110/wekelabifake_pupuz_kuwapufomobove.pdf
    • https://cdn-cms.f-static.net/uploads/4373526/normal_606591f0ec2bf.pdf
    • https://cdn-cms.f-static.net/uploads/4480905/normal_6064e0cb98a19.pdf
    • https://static.s123-cdn-static.com/uploads/4480758/normal_5feeab2c6174c.pdf
    • https://cdn-cms.f-static.net/uploads/4417220/normal_606e4b0f2bbef.pdf
    • https://cdn-cms.f-static.net/uploads/4488330/normal_5fd9304f6f687.pdf
    • https://cdn-cms.f-static.net/uploads/4446399/normal_5fd2d3e073e29.pdf
    • https://cdn-cms.f-static.net/uploads/4401716/normal_6018ebd5a5ea7.pdf
    • https://static.s123-cdn-static.com/uploads/4372967/normal_5fe0d0f153850.pdf
    • https://cdn-cms.f-static.net/uploads/4427526/normal_605a655eadedc.pdf
    • https://cdn-cms.f-static.net/uploads/4484107/normal_603c194246b15.pdf
    • https://dezubawutojowi.weebly.com/uploads/1/3/1/3/131398539/90423a0ab659b.pdf
    • https://cdn-cms.f-static.net/uploads/4447914/normal_5fdc89b491f4a.pdf
    • https://static.s123-cdn-static.com/uploads/4374686/normal_5ff4df2e8b67d.pdf
    • https://cdn-cms.f-static.net/uploads/4393356/normal_602d70db6b61a.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/eaef922f-6965-48e4-ac55-a714c1571370/what_is_prehistoric_art.pdf
    • https://uploads.strikinglycdn.com/files/c2d1fb1d-ec4e-490c-9f27-e392b80a6c40/zixojamaxenad.pdf
    • https://uploads.strikinglycdn.com/files/d8242bbf-b1b4-46df-a30f-ff7eded36ca1/pie_chart_worksheets_7th_grade.pdf
    • https://uploads.strikinglycdn.com/files/a08e097f-4254-4dae-b284-ee18ad634f3c/44121815049.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f767.bin
420636a5304535fb4357ef439dd5f698d447f892182b20d27ff9c13fac84a179
pdf-font-stream PDF embedded font (sfnt) at offset 0xF767 5580 bytes
font_01_sfnt_off00010a52.bin
6417826ea0cb694553b877cfb0095cd8b2066b32491ffee756ce3c73b675cfa6
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A52 11084 bytes