Malicious PDF — malware analysis report

Static analysis result for SHA-256 739d6669933c6f6c…

MALICIOUS

PDF

80.4 KB Created: 2021-09-07 19:13:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 8a4bc91dd5020e85b9c49b34f9439c19 SHA-1: 517aa26fd4fc1590fb603e0e69b727f84e78f3be SHA-256: 739d6669933c6f6c6000212b700f74a0e3669256be7ee7162a9a3184123d6348
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics as containing a link farm pointing to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV also identified it as malicious. While no executable scripts were extracted, the embedded URLs suggest a phishing or redirection attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/89170d54457304d59c5dd71a926f7495/kuwopekitoz.pdf In PDF document text
    • https://comobrew.com/newsite/images/user_uploads/file/nuruvepabuvakawemo.pdfIn PDF document text
    • http://nbpcpentecostalchurch.com/clients/65183/File/75863373719.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609fb7f076f9d---wekuzefa.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/svutmcg4br07peo1squ22d59tv/jofovo.pdfIn PDF document text
    • https://zlato-eu.cz/upload/files/48646144535.pdfIn PDF document text
    • http://agierresrl.it/userfiles/files/76893091691.pdfIn PDF document text
    • https://canionglobal.com/FCKeditor/file/xulekuwanavapometagufod.pdfIn PDF document text
    • http://johncarroll1967.com/clients/1/18/1896e795ecc2602204d707ec4e69586f/File/86322050103.pdfIn PDF document text
    • https://diaochue.vn/userfiles/file/94263536534.pdfIn PDF document text
    • https://hoalavender.net/upload/files/zuvejib.pdfIn PDF document text
    • http://hb1004.com/userData/board/file/97128102239.pdfIn PDF document text
    • http://dansungsala.com/uploads/files/vinavod.pdfIn PDF document text
    • http://inspiredindianfoundation.org/uploads/60079888908.pdfIn PDF document text
    • http://pc-driver.ru/userfiles/files/pigodafujux.pdfIn PDF document text
    • http://xpressup.com/userfiles/file/81861041535.pdfIn PDF document text
    • https://beldapin.com/calisma2/files/uploads/dorulemexobireragop.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f680c97e5f---fomanuvelelipus.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/8cb4a0fb00188f0d74317ca4f8c93b52/zuxoziporunedetugij.pdfIn PDF document text
    • http://akwarella.pl/user_uploads/file/81900355699.pdfIn PDF document text
    • http://wxhsbl.com/ckfinder/userfiles/files/20210710_193637.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=chery+qq+amt+service+manualPDF 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_off0000d6a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6A2 10832 bytes
SHA-256: 238a4ab91a8182ce5e382a78d09d000c657245fedae1a66f255b6544d6214370
font_01_sfnt_off0000ef87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF87 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010799.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10799 16912 bytes
SHA-256: f861648b1b7f4d9f4bb82ca8fc650e9daa11c67ff7c79d1737cd47b1bc46c2e4