Malicious PDF — malware analysis report

Static analysis result for SHA-256 51f2253fae700aa9…

MALICIOUS

PDF

79.1 KB Created: 2021-09-15 14:16:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1ebc18abcecd338cebfee11a221970bc SHA-1: 15dfc61eca0e8e44fd950ce50c0ce7228c578d08 SHA-256: 51f2253fae700aa907a565c9e1c64d657b4ab7d52a7cceb18981593c55e4913b
126 Risk Score

Malware Insights

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

The PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with one heuristic identifying it as a link farm on disposable hosting. The document body is heavily obfuscated, preventing analysis of its specific content, but the presence of many external links strongly suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://nj-rshb.com/v15/Upload/file/20219111121404690.pdf In PDF document text
    • http://fsf-vastroad.com/userfiles/file/6127146559.pdfIn PDF document text
    • https://2b3la571ga-70p.com/contents/files/renod.pdfIn PDF document text
    • http://onnetsolution.in/userfiles/file/98843639133.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/74409335066.pdfIn PDF document text
    • http://ytbozhuo.com/upload/file/140250543435.pdfIn PDF document text
    • http://eva.am/files/36fb6f00153fb03d.pdfIn PDF document text
    • https://bostoncake888.com/UserFiles/files/xuvalu.pdfIn PDF document text
    • http://ylpqzl.com/ckfinder/userfiles/files/94040383077.pdfIn PDF document text
    • http://budka39.ru/files/86691207247.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/161316b9c1de54---75169263395.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136469df2e06---kopulutusulajimeluximore.pdfIn PDF document text
    • http://www.integra-cr.cz/administrace/ckfinder/userfiles/files/mesaw.pdfIn PDF document text
    • http://sibmaxi.ru/userfiles/file/bukofaxumofozewoz.pdfIn PDF document text
    • http://www.drivingschool-brno.cz/files/files/88835721693.pdfIn PDF document text
    • http://nano-vip.com/ckfinder/userfiles/files/95998231008.pdfIn PDF document text
    • http://samtekelektrik.com/files/32355879255.pdfIn PDF document text
    • http://ccsl.asia/files/gogikigiseremexeweraw.pdfIn PDF document text
    • http://clinicaveterinariasangiacomo.it/userfiles/files/71508253051.pdfIn PDF document text
    • http://megaprestige.ru/uploads/files/75285754397.pdfIn PDF document text
    • http://eviljoy.com/UserFiles/File/rugujemepazolusidufap.pdfIn PDF document text
    • https://htchninc.com/d/files/12706872414.pdfIn PDF document text
    • http://dominant.name/userfiles/file/21797979933.pdfIn PDF document text
    • https://netshopnepal.com/userfiles/file/25851749605.pdfIn PDF document text
    • http://biomehl.com/images/content/files/33554967551.pdfIn PDF document text
    • http://rsport.eu/yonexshop/static/file/zofufivapebuzomidur.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=black+desert+mobile+mod+apk+unlimited+moneyPDF 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_off0000cac8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAC8 19088 bytes
SHA-256: 72d8ad69229b2e84ee2d3cd7043353468c00b54ee35320bb038f3ecd23481beb
font_01_sfnt_off0000fcf9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCF9 11176 bytes
SHA-256: 44997da4c5515c3c7231122e335e57bf3e28a2866a015841e90abf06e2677022
font_02_sfnt_off000116ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1