Malicious PDF — malware analysis report

Static analysis result for SHA-256 f832df95ce5cde59…

MALICIOUS

PDF

71.9 KB Created: 2021-09-11 17:54:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 5e9dfae09231de132a4fb59187d27d67 SHA-1: cf0fb7945d8ddc58c4178daf2e1d9cd0d745b38b SHA-256: f832df95ce5cde59ad07125d52f1319d3b3ab175e3ee066354b1539f85f3f630
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting, suggesting an attempt to distribute malicious files. The presence of a link farm and SEO manipulation tactics, combined with a high ML classifier score and ClamAV detection, indicates a phishing or malware distribution scheme. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but the overall structure and URL analysis point to malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://tieclangman.com/Images_upload/files/86786447057.pdf In PDF document text
    • http://fratellilongoni.com/userfiles/files/tuwafufatikalo.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/98673604100.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/1612ecd1cb25f5---kabutonoludanobekev.pdfIn PDF document text
    • http://chelseacarpet.com/ckfinder/userfiles/uploads/63128803423.pdfIn PDF document text
    • https://truongthanhco.vn/webroot/img/files/81188431906.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613249e1a3e20---salax.pdfIn PDF document text
    • http://kxqcgs.com/filespath/files/20210904065303.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/29505051995.pdfIn PDF document text
    • https://baust.edu.bd/app/webroot/ckfinder/userfiles/files/dedepofefogezemazapumemo.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613bd65d375f8---fufapad.pdfIn PDF document text
    • http://bogaarchitetti.it/userfiles/files/84449316698.pdfIn PDF document text
    • http://promocode.lu/userfiles/files/kakoda.pdfIn PDF document text
    • http://zlhk.ru/upload_picture/file/7043336090.pdfIn PDF document text
    • http://yao-cheng.com/uploadfiles/20210831233823.pdfIn PDF document text
    • https://piataafacerilor.ro/app/webroot/files/userfiles/files/66644653315.pdfIn PDF document text
    • http://iamsong.vn/uploads/files/89723512415.pdfIn PDF document text
    • https://highlander-inn.com/assets/userfiles/files/58908552569.pdfIn PDF document text
    • http://besttailor.info/ckfinder/userfiles/files/79018074633.pdfIn PDF document text
    • http://ccswcd.com/userfiles/file/zebimafezup.pdfIn PDF document text
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/d0d94ca5a905698ef32b785652be7f86/dopajawigezizedejidezuma.pdfIn PDF document text
    • https://hram-uspeniya.ru/ckfinder/userfiles/files/47609694016.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=minecraft+1.17+cave+update+download+android+freePDF 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_off0000b5e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5E7 10856 bytes
SHA-256: a1ba45c428ceae473e41d458f9ddae8944e080b317c60f76988cc03fe60d62b4
font_01_sfnt_off0000cf3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF3B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e74d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE74D 16740 bytes
SHA-256: 0b4de6ba9706cb6f8647dc54bb58f9073efe88c7479cd5ff56ce7b2941f2547c