Malicious PDF — malware analysis report

Static analysis result for SHA-256 17ef136efa6d5ae5…

MALICIOUS

PDF

75.0 KB Created: 2021-09-16 22:53:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 6c4045d6bda0697f0042297eba7d78cd SHA-1: ad92dffbcec369da59995166225e4e91c4befebf SHA-256: 17ef136efa6d5ae5460e59fac7c4d38c18fc38e2a2ee419bd8670bf94fc90d83
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are associated with link farms and disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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.
  • 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://queure.ru/uplcv?utm_term=geotechnical+engineering+principles+and+practices+coduto+pdf PDF link annotation
    • http://penzionnakrizankach.cz/ckfinder/userfiles/files/75427905390.pdfIn PDF document text
    • http://hftyby.com/upload_fck/file/2021-9-7/20210907144616583342.pdfIn PDF document text
    • http://cedule-plachty.cz/files/file/65096638845.pdfIn PDF document text
    • http://kursverwaltung.fit-n-essen.ch/ckfinder/userfiles/files/rufemepuzeguniteg.pdfIn PDF document text
    • http://open.ua/uploads/ckeditor/files/14718643475.pdfIn PDF document text
    • https://turismopontevedra.com/ckfinder/userfiles/files/9802627004.pdfIn PDF document text
    • http://xn----7sbakn3aoflleitf3m6a.xn--p1ai/userfiles/file/53732512327.pdfIn PDF document text
    • http://epmachine.ru/d/files/pamobegozenupokowudabu.pdfIn PDF document text
    • http://chafewyuok.handysociality.com/upload/files/jusuj.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/55715935938.pdfIn PDF document text
    • http://steakclubhn.com/campannas/file/sivenufiv.pdfIn PDF document text
    • https://x-software.cz/data/file/42549256842.pdfIn PDF document text
    • http://gyogytornasziget.hu/uploads/files/36692435701.pdfIn PDF document text
    • http://mdknoodles.co/uploads/files/38281672598.pdfIn PDF document text
    • http://vipnovini.bg/root/f/uploads/files/65155634931.pdfIn PDF document text
    • https://jazykovytabor.topenglish.sk/app/webroot/gallery/files/70145485611.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f928933098---levutaj.pdfIn PDF document text
    • http://drsrkbedcollege.com/ckeditor/ckfinder/userfiles/files/delidobimolo.pdfIn PDF document text
    • http://123flower.doweb.kr/upload/files/27577763451.pdfIn PDF document text
    • http://cityfate.com/files/files/92513820650.pdfIn PDF document text
    • https://contact-house.com/fckeditor/upload/file/9939771908.pdfIn PDF document text
    • http://surausa.com/uploads/files/taxudun.pdfIn PDF document text
    • http://fotografiafrancescosomma.com/userfiles/files/muzikolagi.pdfIn PDF document text
    • http://gocchame.vn/app/webroot/img/uploads/files/57414047823.pdfIn PDF document text
    • http://aytekinpolatel.com/image/files/79302533069.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://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_off0000c1c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1C3 11036 bytes
SHA-256: 0eaf5a4d155b81f8a2a6cf20e084514c8ceb8482de3d7a0b5f5d4ee868ec8f82
font_01_sfnt_off0000db36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB36 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f348.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF348 16476 bytes
SHA-256: ec6ea064414dae1cb597d8e68163322c4a1df978afbf577b044850f2eccb6641