Malicious PDF — malware analysis report

Static analysis result for SHA-256 18a775def24348be…

MALICIOUS

PDF

80.5 KB Created: 2021-09-20 21:50:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: c4e282acde19e04aaf469b9b5d29543b SHA-1: e7a47a5a18ef6a74eebeff4766f189850f947e00 SHA-256: 18a775def24348be9531327aa734d4a2596c57f8c954d679aa0e7f3c3cdff156
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body is unreadable, but the heuristic firings strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 http://comlark.ru/userfiles/files/josokegetanuto.pdf In PDF document text
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/rmj3bbqk0v53nlnpbjs4o1hs15/51891961417.pdfIn PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/4c9d94c8a8317b793389ee1315be08b4/19587824674.pdfIn PDF document text
    • http://sonhanint.com/uploadpic/sun/files/202109010730256465.pdfIn PDF document text
    • http://cuoredicane.it/userfiles/files/panefekinubujefulajomumut.pdfIn PDF document text
    • http://ubest.ru/images/file/80824371363.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/c40d53679f786011545d45785650ddd8/53339100151.pdfIn PDF document text
    • http://tinavaron.com/ckfinder/userfiles/files/8108101682.pdfIn PDF document text
    • http://avtrak.ru/ckfinder/userfiles/files/lulomevir.pdfIn PDF document text
    • https://heritran.vn/uploads/news_file/sumonatilipanora.pdfIn PDF document text
    • https://hefcom-hydraulics.com/ckfinder/userfiles/files/gunajuxujigaxogexazobo.pdfIn PDF document text
    • http://ephtour.com/FileData/ckfinder/files/20210914_D6E414D218C24C12.pdfIn PDF document text
    • https://justforjetscatering.com/userfiles/image/files/xugojemiwuj.pdfIn PDF document text
    • https://self-storage.sg/images/uploadedimages/file/fobukoxipanap.pdfIn PDF document text
    • http://bobiniauto.com/userfiles/file/885815075.pdfIn PDF document text
    • http://dostrojar.sk/UserFiles/file/85895992121.pdfIn PDF document text
    • https://cosmopolitanhotelbg.lastrada.bg/uploads/wysiwyg/files/bofasarokupoboj.pdfIn PDF document text
    • http://fu-xin.tw/uploads/files/202109072333447412.pdfIn PDF document text
    • http://apismorava.eu/docs/loxorekutixed.pdfIn PDF document text
    • https://machnik.net/ckfinder/userfiles/files/93633161290.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/18e54433791b4e2e29ebc83cc61b1e64/78808175963.pdfIn PDF document text
    • http://sungwoo-n.com/userfiles/file/65414858841.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=a+doll%27s+house+as+a+problem+play+pdfPDF 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_off0000d48a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD48A 17896 bytes
SHA-256: d036823f70c0bf30b909f8963d6f4cf4ea4388722288d6d95433f95bdbe348d0
font_01_sfnt_off00010317.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10317 10840 bytes
SHA-256: d06f26296d1797534b42e4b274b149917d2c118f8e9b731a84614149c77a9028
font_02_sfnt_off00011bf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BF7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1