Malicious PDF — malware analysis report

Static analysis result for SHA-256 537cf984eb3ecbbf…

MALICIOUS

PDF

83.3 KB Created: 2021-09-09 21:10:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 70a0673e2fbcadf98f947df1933561fb SHA-1: 4b174018403ae22a00f4765bd721a82e4b2362a6 SHA-256: 537cf984eb3ecbbf1e31f194775fed5207c91f691087c828d50dff4257cf613c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan. It contains numerous embedded URLs, many pointing to PDF files on various domains, suggesting a link farm or distribution network. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicates a malicious intent related to SEO manipulation or hosting further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • 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.
  • 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 http://photopuzzle.net/userData/board/file/tugefoli.pdf In PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16139f7e23ec88---munugalodavodezun.pdfIn PDF document text
    • https://langumeistras.lt/i/File/93677064635.pdfIn PDF document text
    • http://vom-ragnaroek.de/uploads/file/79399768100.pdfIn PDF document text
    • https://okud-istra.hr/userfiles/file/52468353694.pdfIn PDF document text
    • http://ilkjv.com/Images/Media/files/43877501864.pdfIn PDF document text
    • https://tomorrowhubs.com/upload/users/files/biwoziwe.pdfIn PDF document text
    • http://21cedu.com/pds/userfiles/files/27490227332.pdfIn PDF document text
    • http://ebonit.light.bg/includes/libs/ckfinder/userfiles/files/68478008427.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/161361fb7e614c---32459026447.pdfIn PDF document text
    • https://whitesal.com/data/images/file/3554_20210910021056.pdfIn PDF document text
    • https://rajatotogroup1.com/contents/files/86027642397.pdfIn PDF document text
    • http://galerie45.com/userfiles/file/9174490438.pdfIn PDF document text
    • http://tokstar.com/_UploadFile/Images/file/8643070586.pdfIn PDF document text
    • https://infrastone.com/userfiles/files/54268290881.pdfIn PDF document text
    • https://quangcaomattroi.com/uploads/news_file/26324466655.pdfIn PDF document text
    • https://licorne-hotel-restaurant.com/userfiles/file/mafeluki.pdfIn PDF document text
    • http://amsasecretariat.fr/userfiles/file/fowogeb.pdfIn PDF document text
    • http://esejsc.com/upload/files/71210004670.pdfIn PDF document text
    • http://deeringbayrealestate.com/userfiles/files/10300267973.pdfIn PDF document text
    • http://aroma-es.red/yamituki-n/uploads/files/57767646741.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/xemuguwa.pdfIn PDF document text
    • https://artistprasanna.com/userfiles/file/28558060975.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=full+friends+reunion+episodePDF 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_off0000d93b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD93B 10308 bytes
SHA-256: c8db19aa1c367656cf1bbdfc6a69683e8eca5b07a5088455d916fd341fc841e0
font_01_sfnt_off0000f074.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF074 20828 bytes
SHA-256: a53a60d9f26a2da318d52f97ee3206137243a58cd9320a746146d1445a30141d
font_02_sfnt_off000127d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1