Malicious PDF — malware analysis report

Static analysis result for SHA-256 53f031c3d6c4e5ef…

MALICIOUS

PDF

79.3 KB Created: 2021-09-19 14:52:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ac733ac3dccdfe4c5fe1250fa03def9c SHA-1: 84fa9176a19f02467014f9b5995ea0f814c46ae8 SHA-256: 53f031c3d6c4e5ef839561e176e41905290c6dce431a0ccf324820c6bd50d4a2
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to other PDF files hosted on compromised or disposable domains. This behavior is indicative of a link farm designed to distribute malicious content or phish for information. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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 https://cructi.ru/uplcv?utm_term=best+cpu+cooler+app+for+android PDF link annotation
    • http://xiangzhuan.tw/upload/files/xokimajevorotemozofubix.pdfIn PDF document text
    • http://vzwsportenmuziek.com/content_docs/19770457045.pdfIn PDF document text
    • https://akamercedes.com/images/uploads/files/11009650288.pdfIn PDF document text
    • http://senvietsystem.com/ckeditor/upload/files/binewodibibu.pdfIn PDF document text
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/24334510432.pdfIn PDF document text
    • http://max-metal.pl/gfx/file/78905361430.pdfIn PDF document text
    • http://delannahotel.com/user_img/file/sagupefurekibomado.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/e7d5c7eafdfa686d031f65ff613f39fb/41731579505.pdfIn PDF document text
    • http://gzbaosui.com/uploadfile/files/bevenililunuwividuzevaduk.pdfIn PDF document text
    • http://dobermanncz.eu/files/40198724678.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/peebfn881mffjo2k907sirumbd/91751366612.pdfIn PDF document text
    • https://www.twibiotech.com/plugin/ce1/ckfinder/userfiles/files/84723924932.pdfIn PDF document text
    • http://www.mediagrand.hu/data/editorfile/43027495506.pdfIn PDF document text
    • http://mrtowing.ca/Lawyers/userfiles/file/jigofunokesubunonaz.pdfIn PDF document text
    • http://okudshava.ru/userfiles/file/tiwamojovofemub.pdfIn PDF document text
    • https://kasihpaham.com/contents/files/76007484649.pdfIn PDF document text
    • http://minhanh.com/files/xixuzukezadoxulamekew.pdfIn PDF document text
    • http://qdjshg.com/files/file/zunikipasatubojelazubolu.pdfIn PDF document text
    • https://smartbrand.ro/mm/file/weximodipe.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f90352abf7---sidoxudiwame.pdfIn PDF document text
    • http://hcbarrett.com/user_area/file/50647130633.pdfIn PDF document text
    • http://irina-beha.com/ckfinder/userfiles/files/1616470951.pdfIn PDF document text
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/c9c2f305db8c0a49cbeb3cd18dd2ed90/50898990469.pdfIn PDF document text
    • http://omeofest.eu/userfiles/files/5957597200.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_off0000d413.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD413 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ec2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC2A 10764 bytes
SHA-256: 20500a27057f3e9716ec0ece53cd1636e1db4fd62d8f574c1045762707e0f565
font_02_sfnt_off0001050e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1050E 16508 bytes
SHA-256: f3f58fa1d502b77144df1be48488f415151706347d39e3bd04f9b0351404cb90