Malicious PDF — malware analysis report

Static analysis result for SHA-256 91c88f8b820f438a…

MALICIOUS

PDF

71.2 KB Created: 2021-10-03 22:24:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 815f579a7f27799a8d768f1422777c5f SHA-1: 1e703753a870fb84e522a165a9b26b393c9bffee SHA-256: 91c88f8b820f438a89615ed8ea07aa1cce2fbdc5833dae16b74dedd7c2654acb
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to compromised WordPress uploads or disposable hosting, indicating a link farm designed for phishing or malware distribution. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://timavoshipsupply.it/userfiles/file/5960331038.pdf In PDF document text
    • https://argumentua.com/i/file/16482568412.pdfIn PDF document text
    • http://eg-connect.com/uploads/editorfiles/file///22207647724.pdfIn PDF document text
    • http://blow-w124.com/js/upload/files/5178805832.pdfIn PDF document text
    • http://autoservizimensi.it/images/fck/file/vesizajaramonifuxilinimit.pdfIn PDF document text
    • http://longchimvac.net/app/webroot/uploads/files/nodebuzevonuviru.pdfIn PDF document text
    • http://tsrmvolontari.it/userfiles/files/11840782797.pdfIn PDF document text
    • http://rootbeadmill.com/upload_fck/file/2021-9-10/20210910204309803364.pdfIn PDF document text
    • http://sziazsauto.com/uploads/files/27743257751.pdfIn PDF document text
    • http://expertcomptablecourreges.fr/michel_courreges/userfiles/file/resisesanez.pdfIn PDF document text
    • http://energosol.pl/images_cms/file/87142551370.pdfIn PDF document text
    • http://lagunaapartman.hu/images/user/file/vupajelenikobexived.pdfIn PDF document text
    • https://www.kindspring.org/inc/ckfinder/userfiles/files/80597760080.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/ca93362eaa4d8ab80aa23a85f2bbe109/jajafiselelivetizadid.pdfIn PDF document text
    • http://changwontour.kr/FileData/ckfinder/files/20210929_12367B0C6280BB92.pdfIn PDF document text
    • http://bmcnx.com/userfiles/file/narovoju.pdfIn PDF document text
    • https://worldmedglobal.com/userfiles/files/55510104466.pdfIn PDF document text
    • http://epmresearch.org/userfiles/files/vozedipufol.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/161408b2ba4d4e---30514698046.pdfIn PDF document text
    • http://teusz.pl/UserFiles/file/85472010246.pdfIn PDF document text
    • https://hglobaltourb2c.com/FileData/ckfinder/files/20210925_5BB6392178A0715C.pdfIn PDF document text
    • https://marblobaths.com/app/webroot/img/files/95857895158.pdfIn PDF document text
    • http://artikos.pl/userfiles/file/fivikevidovug.pdfIn PDF document text
    • https://latework.cz/soubory/77498516764.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/d6b7726642388e844866592d4fd21aca/gatafulatikoj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=covalent+compound+namingPDF 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_off0000b14e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB14E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c965.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC965 10784 bytes
SHA-256: ec35438e8006949446fca1ec5f457a1414933dacc62e39352a52ad9f5b316d34
font_02_sfnt_off0000e1ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FF 17580 bytes
SHA-256: e24774fe71997337411f29d90479dff9839ac756a576ffe1cc4ca06d07995dc4