Malicious PDF — malware analysis report

Static analysis result for SHA-256 91e16f471ba20ec2…

MALICIOUS

PDF

79.7 KB Created: 2021-08-25 17:47:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 726208a2e49187a8eb3fdbe11bfd4328 SHA-1: 1910554d7e12edbfa2b0c88002ef1da2e1a207f9 SHA-256: 91e16f471ba20ec2dd29f42a9906fdeadbe7c83d87bb1f314ae7f59d5788328b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are part of a link farm hosted on compromised or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery through these redirects. The embedded JavaScript may be used to further obfuscate the redirection process or execute additional malicious code.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://catamma.ru/uplcv?utm_term=spring+batch+example
    • http://datong-travel.tw/upload/ckeditor/files/20210703140129.pdf
    • https://jdrum-music.com/uploads/ckfiles/files/sidar.pdf
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609b989156d44---powenerogepokenetumibo.pdf
    • https://vestol.bg/files/file/poniretazaxulo.pdf
    • http://plafondchauffant.fr//img/user/file/37588087205.pdf
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/16075aa4bdbec3---85631252100.pdf
    • https://www.sensormaticltd.com/app/templates/js/ckfinder/userfiles/files/43775060823.pdf
    • http://satisfytech.com/ck/upload/files/vamesafus.pdf
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/e29e56b2b931bf65eb809c3e85643349/tenisezosaf.pdf
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/421f031ba0ed463006cec55bdd7aabd4/2959228501.pdf
    • https://firsatpin.com/calisma2/files/uploads/29103209475.pdf
    • https://stegopackaging.com/wp-content/plugins/super-forms/uploads/php/files/qv977ka0vr68ehapldqqaca6uh/53503899652.pdf
    • http://seoulsquare.com/userfiles/file/vuxejox.pdf
    • http://likebarcode.com/image/files/20210718_171217.pdf
    • http://meskerjager.nl/media/files/maromakodagifof.pdf
    • https://cvsc.co/userfiles/file/62202346894.pdf
    • https://www.clinicaepilepsia.cl/ckfinder/userfiles/files/dokavopozosologasiril.pdf
    • https://watertorens.nl/userfiles/file/53820347477.pdf
    • http://kibbkw.com/uploads/files/zagobagaragozibubumidera.pdf
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/0dde0d744bea2857911aa91e213c9d54/zomubulafuxow.pdf
    • https://engineeredrepinc.com/wp-content/plugins/super-forms/uploads/php/files/6050c227378a6cc276a93c660c890c71/22852072038.pdf
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/4cdcdf3560ee5ebe9fa7c3856a6f7cfc/pabogutulatavotitet.pdf
    • http://hotdeals24x7.com/ci/userfiles/files/61014186583.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_off0000d05e.bin
be8d8df768a45434346a385048dea3147392311e6ceee3dae6394f796be7c851
pdf-font-stream PDF embedded font (sfnt) at offset 0xD05E 10848 bytes
font_01_sfnt_off0000e909.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE909 16792 bytes
font_02_sfnt_off0001011b.bin
848da733180bcd98fc55c31063c793f3c8269c6c5f621d5295ba84e651d74423
pdf-font-stream PDF embedded font (sfnt) at offset 0x1011B 18272 bytes