Malicious PDF — malware analysis report

Static analysis result for SHA-256 f55250f0ac41872b…

MALICIOUS

PDF

68.3 KB Created: 2020-12-20 12:51:38 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 8862b730daf06e8a9a7e9ada6678f162 SHA-1: 2d10b3c88c43b6c9b2d0c55d19affacba27e7f15 SHA-256: f55250f0ac41872be96add1df0d1f10545a4877be009fb3dade15a8167c39c7c
156 Risk Score

Malware Insights

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

The PDF contains a significant number of external links, identified as a link farm, with a primary URL pointing to a suspicious domain. This suggests the document's purpose is to redirect users to potentially malicious content or phishing sites. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://trafffe.ru/strik?utm_term=cafe+castano+in+english
    • https://gabofulonu.weebly.com/uploads/1/3/4/7/134730366/vukufofite.pdf
    • https://cdn-cms.f-static.net/uploads/4421613/normal_5fad54df805d3.pdf
    • https://static.s123-cdn-static.com/uploads/4420434/normal_5fc5d9536ba0c.pdf
    • https://junipupupu.weebly.com/uploads/1/3/4/7/134739756/pozebasakow-pupufa-ximeser.pdf
    • https://cdn-cms.f-static.net/uploads/4378383/normal_5fbb7c42c2e06.pdf
    • https://cdn-cms.f-static.net/uploads/4467027/normal_5fb60b4a7f10d.pdf
    • https://cdn-cms.f-static.net/uploads/4413244/normal_5f984b3024954.pdf
    • https://cdn-cms.f-static.net/uploads/4451561/normal_5fdbb40c3caaf.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/b0ec7f10-2436-46d0-9e1d-b726cb70f56a/bdo_ap_brackets_2019.pdf
    • https://uploads.strikinglycdn.com/files/a029e939-cf19-4c52-b5ac-c84a10bb0c52/ok_career_guide_kuder.pdf
    • https://uploads.strikinglycdn.com/files/ebd3121a-f6ee-4c79-9116-47db07714d08/suffolk_county_clerk_online.pdf
    • https://uploads.strikinglycdn.com/files/810e078f-03d3-476b-a586-d43e4742fb52/9941310709.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_off0000cf24.bin
f2833440caa8568181fae80c93fc4f67743f60c072f7c9ee8639912f6c214cb8
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF24 4952 bytes
font_01_sfnt_off0000dfff.bin
758adace0dcf27117cd1f6d6a7fb85244835019ab787d242c4829e00824c07a8
pdf-font-stream PDF embedded font (sfnt) at offset 0xDFFF 11204 bytes