Malicious PDF — malware analysis report

Static analysis result for SHA-256 5767597d91260bc5…

MALICIOUS

PDF

85.6 KB Created: 2021-10-05 08:51:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 6a15bae6c752ec8759579464cb2764fd SHA-1: 29b83d454d47d86800547ad824d8e4d5ea29f3fa SHA-256: 5767597d91260bc52f9e23b4d53830de1cab6b967a75c13bb9dabd0dd2de27d3
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 compromised websites or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and appears to be non-readable content from the wkhtmltopdf tool, rather than user-facing text.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://agataklimowska.pl/userfiles/file/sajedijeba.pdf In PDF document text
    • http://jhdljz.com/userfiles/file/1630814671.pdfIn PDF document text
    • http://topup-fight.com/ckfinder/userfiles/files/munanisizejumoxozasibova.pdfIn PDF document text
    • http://apnm.indexint.net/ckfinder/userfiles/files/8467154579.pdfIn PDF document text
    • http://solamsys.com/userData/board/file/20964602945.pdfIn PDF document text
    • https://pixel.bg/img/file/59108353028.pdfIn PDF document text
    • http://wpchkg.com/upload/image/file/98666716426.pdfIn PDF document text
    • https://fpcofmacon.com/nbloom/fckuploads/file/59192659348.pdfIn PDF document text
    • http://trungtinjsc.vn/upload/FCK/file/larabiwomipe.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/73a50d2bdedec1ba55be64ea523b45cc/nogupajevewe.pdfIn PDF document text
    • http://nissanotogovap.vn/uploads/images/files/pefilumip.pdfIn PDF document text
    • http://bestorkate.com/uploads/ckeditor/files/dibebiwovomivedanodetuwo.pdfIn PDF document text
    • http://sinoscaform.com/upload/ckimg/files/202109161052455210.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1615a19e62b978---dovivogosunuzumujazane.pdfIn PDF document text
    • https://karapinarinsaat.net/userfiles/upload/file/95890593443.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/16140d4a2382ab---vupuzafufusodowolipedakov.pdfIn PDF document text
    • http://paradisetourkorea.com/FileData/ckfinder/files/20210916_5E053A3E569CBF4E.pdfIn PDF document text
    • https://praktijk-fix.nl/userfiles/image/file/26733080466.pdfIn PDF document text
    • https://servingltda.com/userfiles/file/10119030859.pdfIn PDF document text
    • https://nhahangbienhaitien.com/uploads/files/53148739437.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/tru6ulp0e2hi9evrgjt53jvcr5/rixut.pdfIn PDF document text
    • http://innotack.com/userfiles/files/66674948381.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=dravidian+etymological+dictionary+pdfPDF 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_off0000dccd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCCD 22316 bytes
SHA-256: eff878ddcada1db341435158e3d9b28b95788dddeff85db3e086a5a638536341
font_01_sfnt_off0001174e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1174E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012f65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F65 10976 bytes
SHA-256: c84e2751d52229e593db3c71a0d69c8426b4d1892da8d3fc3115ece5651c5197