Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ea3aa0d7683fc25…

MALICIOUS

PDF

80.8 KB Created: 2021-09-16 07:50:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 7d05dece6458a5198dca1224b85222c1 SHA-1: 7c44accc7bde793322c46b94e49ee3d61cadfa26 SHA-256: 8ea3aa0d7683fc254e0f5cfc13424132c66bd3644c392b93b9ad896fc2881339
206 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF document employs a social engineering lure, instructing the user to install a browser extension or update to view content. This is a common tactic to facilitate credential theft or malware installation. The presence of multiple external links, including one pointing to a potentially malicious URL, further supports this assessment. ClamAV detection and ML classification confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://cructi.ru/uplcv?utm_term=chrome+update+apk+download PDF link annotation
    • https://kham.vn/userfiles/file/2376836933.pdfIn PDF document text
    • http://xn--9p4b29dncp2cc6y.net/upload/fckeditor/file/sogekulipolopipomisixoxa.pdfIn PDF document text
    • http://syntra.pl/userfiles/file/mewafamunelapome.pdfIn PDF document text
    • http://mertcelikkapi.com/userfiles/file/varurujezowovarunokesapix.pdfIn PDF document text
    • http://studiomedicoveterinariobellucci.eu/userfiles/files/98896840453.pdfIn PDF document text
    • http://malovanesklomh.cz/images/file/bokotudobovilov.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614047547fbe5---zijopamizebilefubimulalax.pdfIn PDF document text
    • http://melodylavernebettencourt.com/media/file/45172704193.pdfIn PDF document text
    • https://umartravel.com/files/jesinopejurupesurepavajim.pdfIn PDF document text
    • https://promaxsuspension.com/csmimage/file/41063613263.pdfIn PDF document text
    • http://distant-property.ru/fck_editor_files/files/wevopujugevosilegizo.pdfIn PDF document text
    • http://grupafurman.pl/!mag2011/userfiles/file/19131471928.pdfIn PDF document text
    • http://ukonlinedirect.com/userfiles/files/xapaxatujinagabokijadupe.pdfIn PDF document text
    • https://pasarangroup1.com/contents/files/53033084660.pdfIn PDF document text
    • http://ediljolli.com/userfiles/files/31918885857.pdfIn PDF document text
    • http://ranchobg.com/img/file/vibexunuzojixesenu.pdfIn PDF document text
    • http://webinaris.eu/ckfinder/userfiles/publics/files/19363617188.pdfIn PDF document text
    • https://eghamatkade.com/basefile/eghamatkadecom/files/14441136918.pdfIn PDF document text
    • http://nocleginaplus.pl/uploads/userfiles/files/soges.pdfIn PDF document text
    • http://ptk-tent.ru/userfiles/file/xejupiwoseminorosutini.pdfIn PDF document text
    • http://tianfonmm.com/d/files/rowexor.pdfIn PDF document text
    • http://biurod9.pl/public/userfiles/file/33953431201.pdfIn PDF document text
    • http://balassalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/72982221285.pdfIn PDF document text
    • https://morabia.fi/images/file/94853865994.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d897.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD897 17384 bytes
SHA-256: 32a84b3467e03c587f5bdefcabb0c21c34954de4d93e374222f05eed0eecc904
font_01_sfnt_off00010505.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10505 10704 bytes
SHA-256: 7c235375d03837bd8f96f4548df4a02b5e05d26e117bd17c6262a8c08476ea68
font_02_sfnt_off00011d7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D7D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1