Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc6876ab7ec9b26c…

MALICIOUS

PDF

78.8 KB Created: 2021-09-12 02:51:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b330d2c0556edb7124f4c648433b5850 SHA-1: 788cc9f306fc8e8f0077581f61760771dbd81f25 SHA-256: fc6876ab7ec9b26caa406a84ec23427394e41bf16bd35033ca276b9117c70a26
166 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to disposable domains, which is characteristic of a link farm used to obscure malicious destinations. The heuristic 'PDF_RANDOM_URL_LINK' specifically flags a link to a PDF hosted on a suspicious domain, indicating a likely attempt to deliver a secondary malicious payload. The ML classifier and ClamAV detection further support the malicious nature of this document.

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 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.
  • 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://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d2f1095db6---52455238322.pdf In PDF document text
    • https://asiarsolutions.com/userfiles/file/xilula.pdfIn PDF document text
    • http://capriololaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/wumanu.pdfIn PDF document text
    • http://exms.fr/sites/default/files/file/92978208236.pdfIn PDF document text
    • http://www.satunatc.ac.th/ckfinder/userfiles/files/gomobuxosugizubexufula.pdfIn PDF document text
    • https://galaxy-training.com/userfiles/file/35540829560.pdfIn PDF document text
    • https://seeandhearbetter.ie/img/shop/contents/gazejegovomudosewil.pdfIn PDF document text
    • http://lucidarepavimentimarmogenovaealessandria.it/userfiles/files/jujerugakowegokojev.pdfIn PDF document text
    • http://nesemlak.com/test/images/uploads/files/38795942503.pdfIn PDF document text
    • http://nguyenthaotech.com/upload/files/3413632736.pdfIn PDF document text
    • https://www.bevillelecomte.com/ckfinder/userfiles/files/vugimuwunupowo.pdfIn PDF document text
    • http://patronusalapitvany.hu/public_html/upload/makemarof.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/5b6e3728c034f6a0111d4cc029d4de44/ramepezi.pdfIn PDF document text
    • http://xy-interior.com/uploads/files/202109012111021350.pdfIn PDF document text
    • http://paglialonga.it/userfiles/files/29915481105.pdfIn PDF document text
    • http://tcihk.com/userfiles/nagixugoriwuwenufoz.pdfIn PDF document text
    • http://kompletucetnictvi.cz/files/file/86969958814.pdfIn PDF document text
    • https://butagallery.com/userfiles/files/93349469124.pdfIn PDF document text
    • http://selidbe-beograd.info/files/52721947824.pdfIn PDF document text
    • http://home-plast.ru/foto/files/tagesufemudakurotu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=textbook+of+biochemistry+for+medical+students+9th+edition+pdf+free+downloadPDF link annotation
    • 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_off0000cd9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD9E 11648 bytes
SHA-256: 91f9c7aa126ab3fa3c584f2e9cc6ee86cfdaeeb7e853723dfa539141b99225a9
font_01_sfnt_off0000e914.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE914 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010126.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10126 17068 bytes
SHA-256: 3effba15605aac191f1ed81646547177dfcc495755060a94495a6531ecec4957