Malicious PDF — malware analysis report

Static analysis result for SHA-256 caf2359ff97e865a…

MALICIOUS

PDF

77.4 KB Created: 2021-09-20 09:05:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6972ddd03b3de4e6c748481359f53b3c SHA-1: 74d7d8f10e608dce59975b6f71e6bc51f90df8e8 SHA-256: caf2359ff97e865a6d76a85e478229133d2a843bfedcccf1e6cb857bf65e701d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, many pointing to compromised websites or disposable hosting, indicative of a link farm used for phishing or malware distribution. The ClamAV detection and ML classifier strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://coretry.ru/uplcv?utm_term=advanced+data+structures+notes
    • https://graveyards-fuj.ae/userfiles/files/93571345631.pdf
    • http://okeefesreef.com/ckfinder/userfiles/files/53101507792.pdf
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/16132c4915789d---vinagiridabifasabezib.pdf
    • http://xatrbio.com/userfiles/file/62504514024.pdf
    • http://trovas.com/userimages/46996493767.pdf
    • http://dallapietamarchisio.it/userfiles/files/gozabaxerepariwibuj.pdf
    • http://kechengchem.com/upload/files/pagubolesatotutideme.pdf
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/16146c53ee8624---79809992275.pdf
    • https://mallncart.com/userfiles/files/fimomeligibimamozupo.pdf
    • https://infiniteprospects.com/FCKeditor/file/jopipaxaniroj.pdf
    • http://dasbluemchen.com/88466640368.pdf
    • http://theponghop.com/upload/files/lapozuxovezegipeninomutad.pdf
    • http://klick-tipp.info/ckfinder/userfiles/publics/files/daveredisirupatad.pdf
    • http://slesnick.net/userfiles/files/14159208773.pdf
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612edefcad865---lababefebotepivi.pdf
    • http://ykzn8.com/upfiles/editor/files/votezoleroketulefedix.pdf
    • https://digireg.sk/upload/kefabilizenesulitipufid.pdf
    • https://klubkanine.com/home/klub/public_html/ckfinder/userfiles/files/41128682193.pdf
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/f23b4de63909c24cf906d5894fe4d8fc/zavonavi.pdf
    • http://gamax-motor.cz/data/dokumenty/69333268656.pdf
    • http://fashionflutters.com/ckfinder/userfiles/files/81322069558.pdf
    • https://terminal.hr/userfiles/file/fidujone.pdf
    • https://idea-web.ro/app/webroot/files/userfiles/files/bewukenikelo.pdf
    • https://odlingfamily.com/userfiles/file/zufuzapaxix.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_off0000c8c3.bin
d0617cd4d0ef2d2c71841b37fc0e4659f9a01815bd93bbcf886df899856c8509
pdf-font-stream PDF embedded font (sfnt) at offset 0xC8C3 18128 bytes
font_01_sfnt_off0000f85b.bin
3307d01c0497020d0e85d237ed19572b5d781a24baf11f32cd28b9c69cced94a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF85B 10372 bytes
font_02_sfnt_off00011008.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11008 16792 bytes