Malicious PDF — malware analysis report

Static analysis result for SHA-256 641b3acd79819067…

MALICIOUS

PDF

69.9 KB Created: 2021-09-26 08:37:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: fc78b32dd41eaa26358dca6446a18db8 SHA-1: 880a929a80e898f744c27a7d1b19fbf33c68adde SHA-256: 641b3acd79819067e2ad62898ba3c1f7c7e0dd5ef9be594388e4a6a088028728
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS uploads or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious PDF lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

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://vektor-bezpeki.com/userfiles/files/dasuwudojevet.pdf In PDF document text
    • http://nutrizionisti.eu/public/thread/risorse/file/dupabuba.pdfIn PDF document text
    • https://petpetmates.com/files/editor/file/xozupuselupatoxulope.pdfIn PDF document text
    • https://smg.bid/ckfinder_userfiles/files/94620376846.pdfIn PDF document text
    • https://vwb.mrv-educationservices.com/content_file/files/duxuzusa.pdfIn PDF document text
    • https://jasz-pap.hu/UserFiles/file/kadibemogizarido.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131d373c7aeb---66583939751.pdfIn PDF document text
    • http://tg-focus.ru/userfiles/files/rijajag.pdfIn PDF document text
    • https://holcom-solar.com/webroot/img/files/zokubenoguzutigawux.pdfIn PDF document text
    • http://about-dogs.ru/upload/file/vesuzi.pdfIn PDF document text
    • http://katyababash.com/images/uploads/file/wamelitakomakuganonako.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b411c77535---31312281192.pdfIn PDF document text
    • http://liccuza.ro/stiri_files/file/46705545803.pdfIn PDF document text
    • https://eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/93938088386.pdfIn PDF document text
    • https://audreyheselmans.com/_files/file/91347654720.pdfIn PDF document text
    • http://hfnhsw.com/upload/files/bixazodebakewopa.pdfIn PDF document text
    • http://vncdata.net/app/webroot/uploads/files/83896403147.pdfIn PDF document text
    • https://kirmatas.com/userfiles/file/96975862663.pdfIn PDF document text
    • http://italy-ex.com/images/blog/file/wevafaseduvugifopaxirafib.pdfIn PDF document text
    • http://podolsk-kondicionery.ru/upload_picture/file/87470547581.pdfIn PDF document text
    • https://bestcaps99.com/ckfinder/userfiles/files/27146997813.pdfIn PDF document text
    • https://kmkmekanik.com/upload/ckfinder/files/bosaba.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141f3cade2ed---50887015318.pdfIn PDF document text
    • http://investbuild.ru/var/upload/file/57187202732.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/c3197ec8b23b25a91b96bd16edb34c5c/fuzijigimaxefapibuweba.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1614770126751a---23008190764.pdfIn PDF document text
    • http://solmoda.it/userfiles/files/33551457643.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=how+to+send+large+video+files+on+facebook+messengerPDF 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_off0000b33f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB33F 14456 bytes
SHA-256: 818a3e78182003ea003142529cf0e43308dab4b4550e197e68c9c1daafe9443f
font_01_sfnt_off0000d783.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD783 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ef9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF9A 11192 bytes
SHA-256: 62665b327999080d2b4949524d95c91402063996e67afad67bd0c6fa8ad41fb3