Malicious PDF — malware analysis report

Static analysis result for SHA-256 7645d34d106ba1d4…

MALICIOUS

PDF

69.6 KB Created: 2021-09-18 09:51:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 74a9ebc9fe54f42266823b1512902152 SHA-1: b3e1dc02c438c8476e8cdd76e5b2aa464bd9973a SHA-256: 7645d34d106ba1d4a026d83a5295da4b5d341d205864ace1eced2600e45a730e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs, many pointing to disposable hosting, suggesting a link farm or phishing lure. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it is designed to redirect users to potentially harmful external sites, aligning with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://itandem.net/ckfinder/userfiles/files/9199541100.pdf In PDF document text
    • http://xszhuhai.com/uploadfiles/files/2833851355.pdfIn PDF document text
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/83696bc359a3a10a1b87dcab39edcbff/53943672742.pdfIn PDF document text
    • https://testgit.begurholidays.com/uploads/userfiles/files/luvulij.pdfIn PDF document text
    • http://soyaksiesta3.com/userfiles/file/32965576194.pdfIn PDF document text
    • http://rent-lease-no1.com/userfiles/file/20210910004852.pdfIn PDF document text
    • http://uspeh-kursk.ru/ckfinder/userfiles/files/54260844152.pdfIn PDF document text
    • http://www.mamafoundation.cz/ckfinder/userfiles/files/91916668229.pdfIn PDF document text
    • http://hantechwelding.com/userfiles/file/2021090823561873499.pdfIn PDF document text
    • http://pusancard.com/userData/board/file/61467602596.pdfIn PDF document text
    • http://mdtrend.hu/files/file/jovodumituruzi.pdfIn PDF document text
    • https://www.db-ynox.fr/ckfinder/userfiles/files/bazalovufowiwasol.pdfIn PDF document text
    • http://www.satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/xutakorejiragurufapux.pdfIn PDF document text
    • http://tayles.com/uploaded/67865742997.pdfIn PDF document text
    • http://azbuka-d.ru/ckfinder/userfiles/files/57968932608.pdfIn PDF document text
    • http://sireny.net/share/files/67848362662.pdfIn PDF document text
    • http://ancient-theater.gr/media/file/60917645102.pdfIn PDF document text
    • https://ou-ravda.com/ckfinder/userfiles/files/fiwunizu.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/30819849948.pdfIn PDF document text
    • https://ewastexperts.com/userfiles/files/57854194834.pdfIn PDF document text
    • http://chonburi33.com/userfiles/file/96769681871.pdfIn PDF document text
    • http://stomerijindex.nl/images/uploads/sebubifa.pdfIn PDF document text
    • https://alihuata.com/userfiles/file/18960735988.pdfIn PDF document text
    • http://khonggianxua.samdigroup.vn/app/webroot/upload/files/11557032790.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=speed+post+suratPDF 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_off0000b294.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB294 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000caab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAAB 10320 bytes
SHA-256: 1d8230ba2ab1aca2bfedc652f9214a7c43ea14faa7c27e9c17ebe2cb3b1dce92
font_02_sfnt_off0000e208.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE208 15312 bytes
SHA-256: 5d3abbf08fb76268c941f0cd000afcf4469f98920e9fa4915704ee45d79ae7b2