Malicious PDF — malware analysis report

Static analysis result for SHA-256 5fdea8c3266a7c31…

MALICIOUS

PDF

77.0 KB Created: 2021-07-13 01:22:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f77f1853bd480ad5320912b390a4f47c SHA-1: ddf7dba884d4764f1fcf0f1e7dde1050500611c4 SHA-256: 5fdea8c3266a7c31e55246498be8d28b35b252cc3aec5e07c0a05a2e7f93d8ef
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_URI and EMBEDDED_URL heuristics further supports the attack pattern of directing users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ketchas.ru/uplcv?utm_term=fairest+lord+jesus+lyrics+and+chords
    • http://musicupclose.com/clients/f/f7/f7c291dfb329fbc33054893077acf627/File/kiwoxavanexijirerages.pdf
    • http://anma.pl/anma_edytor/file/jegot.pdf
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16082ae477f4ee---zuzekukijamawajogudow.pdf
    • http://codemessaging.net/ckfinder/userfiles/files/batekijumupavofopex.pdf
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/nu1tt3066kq19d005og26nu65f/dilemabonofopinot.pdf
    • http://canhtoanland.com/upload/files/gavajaliluwugabuxajuz.pdf
    • http://dhsclassof70.com/clients/d/d1/d13f49183e6b2ef720c1f353b43de0f2/File/9399475321.pdf
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/vnigmeafeocn8u6fiect59vp93/fuvevala.pdf
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/1607b67267428e---dakagazavovag.pdf
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/eriqsplcc046n789chu7ct2s4a/91448495757.pdf
    • http://kudusde.org/resimler/files/kikizevunidev.pdf
    • https://qqhanoman.com/contents//files/33525124633.pdf
    • http://gumberryoleschool.com/clients/33891/File/zorezojusutoxuwogufewijij.pdf
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/cb3d55985219d24d7346f80245c806d2/93190443220.pdf
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160b33e3189c6e---58710092148.pdf
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/q8a1eg9htkb0qs31iocrgv23tf/86013357198.pdf
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1606cadeab021b---5675082120.pdf
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/7mtom284j25sq4vhe4dcmuqaaf/20707890491.pdf
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/2ba1fe7d50c796341b1a2a31289001a3/puvuwafovew.pdf
    • http://seoulsquare.com/userfiles/file/99091279530.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_off0000c8a3.bin
e95db547d271437e4633c5334087f96779e4e51b0ddc455a9ce9ec787a5b276a
pdf-font-stream PDF embedded font (sfnt) at offset 0xC8A3 10788 bytes
font_01_sfnt_off0000e167.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE167 16792 bytes
font_02_sfnt_off0000f979.bin
06baf35ef9f4c217f138e5606615d7a64d567cd8252e959c42b50d26b7b1bba9
pdf-font-stream PDF embedded font (sfnt) at offset 0xF979 16672 bytes