Malicious PDF — malware analysis report

Static analysis result for SHA-256 e77a3e403e53cc0d…

MALICIOUS

PDF

78.0 KB Created: 2021-09-12 10:35:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: f071e955d0ceb76a16ad815ceb5f03fb SHA-1: 0cf48964bd962cbe39f2a48eeb14f78f399823d6 SHA-256: e77a3e403e53cc0d49d05312655a3f2524475f90ebde7bf58906b831c6d536be
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and numerous external URIs, many pointing to disposable domains, suggests a phishing or malware distribution scheme. The document body, though heavily obfuscated, contains metadata indicating it was generated by wkhtmltopdf, a tool sometimes used to create malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9927

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
  • 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://chcial.ru/uplcv?utm_term=download+farming+simulator+18+free PDF link annotation
    • http://bon-mar.com/fck_user_files/file/verojisu.pdfIn PDF document text
    • http://gd-weimi.com/upfolder/e/files/20210912044836.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/2f04ce482a6e12e5ae5c5fc90e9dfa19/8452447876.pdfIn PDF document text
    • http://kompassztuki.pl/Image/files/53953460872.pdfIn PDF document text
    • https://hanurichurch.org/ckfinder/userfiles/files/relujagekor.pdfIn PDF document text
    • http://entryexpress.online/chapter_images/files/desezizobezokagasemi.pdfIn PDF document text
    • http://leasingtowers.com/ckfinder/userfiles/files/39781613116.pdfIn PDF document text
    • http://ordineveterinarivenezia.eu/userfiles/files/pirakiraxaruxugow.pdfIn PDF document text
    • https://china-glass-mosaic.com/userfiles/files/20210906_160343.pdfIn PDF document text
    • http://yibetter.com/data/files/45937504275.pdfIn PDF document text
    • http://rotarybrescello.it/userfiles/files/87645588255.pdfIn PDF document text
    • http://hotelbellevuepalermo.com/userfiles/files/fikosikukezoxedusewifimas.pdfIn PDF document text
    • https://semut73.com/contents/files/32200138170.pdfIn PDF document text
    • http://orsini-blasioli.it/userfiles/files/34437457105.pdfIn PDF document text
    • http://rama-sp.com/rama/webroot/js/ckfinder/userfiles/files/wadefitodobal.pdfIn PDF document text
    • http://abwnickersonplaza.com/uploads/files/95561866408.pdfIn PDF document text
    • https://rougezenekar.hu/files/file/rimuroxijiwikolikibe.pdfIn PDF document text
    • http://costanzolegal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/89921492373.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16132bdd93cc34---fulozetelirapiwulone.pdfIn PDF document text
    • https://www.cifphosteleriayturismo.es/ckfinder/userfiles/files/72071046535.pdfIn PDF document text
    • http://chatyzvule.cz/uploads/pebanajizasol.pdfIn PDF document text
    • http://getsolarny.com/userfiles/file/nasesiwijaf.pdfIn PDF document text
    • http://www.koeru.eu/failid/file/53510328335.pdfIn PDF document text
    • https://rt9.rspo.org/ckfinder/userfiles/files/34074726634.pdfIn PDF document text
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b8b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8B4 11144 bytes
SHA-256: 3bb052c5bca435310b36f7cc146365d24a87e54d15e1de287e05f49f18b26f42
font_01_sfnt_off0000d298.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD298 1820 bytes
SHA-256: ef4c56b83544acc0eae329b123dcb13384a4443b8ee25b6b011fcec9f25c534c
font_02_sfnt_off0000db1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB1E 21472 bytes
SHA-256: 2426d202a1ad6ccb8283d9510a57d861fa1e70bb3f8cdb5f01e6073195f69240
font_03_sfnt_off000111ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1