Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5b0023212f10a09…

MALICIOUS

PDF

73.0 KB Created: 2021-09-24 12:28:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: ab50167d9cd0317cf12824894e892472 SHA-1: 57ea448ceea7cfe25b8a3d9a8b11c338c88fb837 SHA-256: c5b0023212f10a09d0721cacb23829daee35a019e0c6095c593a60fe034dadcc
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains embedded JavaScript and numerous external URIs, indicating an attempt to redirect users to potentially malicious sites. The PDF structure and the presence of JavaScript suggest it's designed to exploit vulnerabilities or trick users into downloading further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://skvely-kup.cz/files/file/deloresakuwudijejufejas.pdf In PDF document text
    • https://malabarmail.com/ckfinder/userfiles/files/85652104124.pdfIn PDF document text
    • https://www.colegiodomus.com.br/js/ckfinder/userfiles/files/62629596599.pdfIn PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/sawamolasedikapuv.pdfIn PDF document text
    • https://oncallanatomist.com/ckfinder/userfiles/files/wuguserusiretoledewodero.pdfIn PDF document text
    • http://brbud.pl/userfiles/file/pivesim.pdfIn PDF document text
    • https://szamitogep-szerviz-javitas.hu/ckfinder/userfiles/files/44169536557.pdfIn PDF document text
    • https://zmiz.hr/userfiles/file/77927318892.pdfIn PDF document text
    • https://sunnyvale.com/wysiwygfiles/file/84397767554.pdfIn PDF document text
    • http://samtle.net/ckupload/files/pifuvata.pdfIn PDF document text
    • http://akicgiyim.com/userfiles/file/sowijilekedokil.pdfIn PDF document text
    • https://stepweystudy.com/ckfinder/userfiles/files/bunizuwumifurewoju.pdfIn PDF document text
    • http://topbuild.net/content/xuploadimages/file/bulajozapilufemobolo.pdfIn PDF document text
    • https://paeonia.ch/userfiles/files/rexodifupos.pdfIn PDF document text
    • http://iwayman.com/uploadfiles/file/2109230545204451213engbv.pdfIn PDF document text
    • http://chroscina.com/userfiles/file/47246835040.pdfIn PDF document text
    • http://jyotiacademicpress.org/uploads/file/gagoza.pdfIn PDF document text
    • https://www.liftechforklifts.com.au/application/third_party/ckfinder/userfiles/files/xumoxewutekejizeb.pdfIn PDF document text
    • https://ismet.com.br/ckfinder/userfiles/files/luwozujizoxokazomawe.pdfIn PDF document text
    • http://itexpertdog.nwoasis.com/upload/files/jilogegutitisiwibam.pdfIn PDF document text
    • http://dyglas.com/userData/board/file/63536952714.pdfIn PDF document text
    • http://christopherdallo.com/file/25550377370.pdfIn PDF document text
    • http://www.its-dph.cz/admin/fckeditor/editor/userfiles/file/topuvupufovanudotu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=how+do+i+turn+on+weather+alerts+on+my+phonePDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b9cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d1e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1E4 10948 bytes
SHA-256: edd6425f370af5f4cd846b72dd71ee9bfd99d7ae8f7983311e7763a7e4436d1b
font_02_sfnt_off0000eb12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB12 16616 bytes
SHA-256: cabdb9cd1e70cb60ff5c248808e1571864bfca2aa878c992f9d4e9e4e3baac16