Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b8c51727c831a88…

MALICIOUS

PDF

87.2 KB Created: 2021-09-07 03:06:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3f6b3a158b8dfecd09f3222247955e8e SHA-1: 18d88ac16c117a773fde8e1817b2981cc0ffe89e SHA-256: 4b8c51727c831a88fab5c45e4c740976c2c2c194e693e2f011cb87fbcd24eae2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of links, many pointing to compromised WordPress uploads, indicating a link farm designed to distribute or host malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://anna-bel.com/app/webroot/files/userfiles/files/2505469748.pdf
    • http://www.blueoak.fr/image/file/xijisalimorubume.pdf
    • https://whitesal.com/data/images/file/1145_20210517044919.pdf
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/161026529a5ab7---53126236130.pdf
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607778dc566c2---gizupugoroxiro.pdf
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fb24eb86e1c---lipelamaniz.pdf
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce99e7182c5---fujetobiluzixixap.pdf
    • https://damsindia.org/admin/uploads/file/93194296001.pdf
    • http://overtonnation.com/clients/f/f9/f97855507a39dfa58978186db9bff07a/File/63517805914.pdf
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/161237ef5e8a4f---54655347319.pdf
    • https://pointswestliving.com/ckfinder/userfiles/files/pulelatujiwaruwirirate.pdf
    • http://tyextractor.com/d/files/rebagudofamifejewafi.pdf
    • http://fulns.com/uploadfile/fckedit/file/1629577084YP5R.pdf
    • https://g4m3s-4p1-12s1.com/contents/files/reluvekavipuzusenakala.pdf
    • http://libertyquad72.fr/userfiles/file/9646684094.pdf
    • http://gd-weimi.com/upfolder/e/files/20210904072557.pdf
    • http://nesthomes.in/userfiles/file/vopajamufejisarar.pdf
    • http://studiotecnicodavico.eu/userfiles/files/fupowutobijelulewefowefav.pdf
    • http://jcon-aps.dk/userfiles/file/38470555050.pdf
    • https://www.ltgpartners.com/wp-content/plugins/super-forms/uploads/php/files/fa2cf116057d71c4e4b8e571ce6055c3/26506514023.pdf
    • http://lussoleathertiles.com/test4/EDITOR/example/v2/userfiles/file/lodaguxiwoxarexu.pdf
    • http://natpuedu.in/userfiles/file/fufozofulejekewiburovi.pdf
    • https://wemservice.com/ckfinder/userfiles/files/75955902967.pdf
    • http://peaceinsrilanka.lk/ckfinder/userfiles/files/voguzawulijazonoli.pdf
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/1bfeb759d929793e8464f50d0b335f2a/difuvi.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=an+introduction+to+forensic+linguistics+language+in+evidence+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea6e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA6E 16792 bytes
font_01_sfnt_off00010280.bin
79796fddbd9b72c4de5a14039f24fd922fc6ff3c0dc47e75a2f705b94f8a556b
pdf-font-stream PDF embedded font (sfnt) at offset 0x10280 19476 bytes
font_02_sfnt_off000134fc.bin
918c8e8a0212aa9525f04df70d7937d3dff637a28950b3d738d159ac5eadb4a9
pdf-font-stream PDF embedded font (sfnt) at offset 0x134FC 10940 bytes