Malicious PDF — malware analysis report

Static analysis result for SHA-256 81f8b71574e23e3f…

MALICIOUS

PDF

71.7 KB Created: 2021-09-12 15:22:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: fe36571d777216fe6e6ac260d3d2178b SHA-1: 8576d4ec9e295a4dfdb9af5efd8d408e6e7d9529 SHA-256: 81f8b71574e23e3f42cf10d64ec086f40fad7c8bbfdb53bd6a85b23d5755acbb
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable domains and are structured as link farms, a common tactic for phishing or distributing further malware. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the PDF structure and URL patterns suggest it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://kondicionery-domodedovo.ru/upload_picture/file/42698655412.pdf In PDF document text
    • http://huyndaicaudien.com/upload/files/fagaru.pdfIn PDF document text
    • https://avphunter.ro/ckfinder/userfiles/files/jekipibafinafapuwareliv.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/4s15u22spp0caseadgnm6dunl2/tevevekekalujelin.pdfIn PDF document text
    • http://ssanadia.in/userfiles/file/fawibexosipibeditomege.pdfIn PDF document text
    • http://attep.com/home/sandbox/domains/heekee.com.hk/public_html/ckfinder/userfiles/files/nawavit.pdfIn PDF document text
    • http://enotecagaribaldi.it/userfiles/files/4096035648.pdfIn PDF document text
    • http://qualityspices.in/ckuploads/files/31165497146.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/37923609197.pdfIn PDF document text
    • http://perlawarmii.pl/userfiles/file/kuxududavamunogopiluk.pdfIn PDF document text
    • http://alsace.annuaire-regional.com/ckfinder/userfiles/files/33675645195.pdfIn PDF document text
    • https://adium.ru/userfiles/file/98543104950.pdfIn PDF document text
    • http://opersan.com/file/lokivexujupewameso.pdfIn PDF document text
    • https://trexanh.net/upload/files/75846655165.pdfIn PDF document text
    • http://lynhuagiasi.com/Images_upload/files/81349712361.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/90610970694.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/19624817584.pdfIn PDF document text
    • http://atreve.eu/ubezpiecz/obrazy/file/foruzemuvokojufapubutemu.pdfIn PDF document text
    • http://supermarketdv.ru/files/file/kakid.pdfIn PDF document text
    • https://99shayari.in/userfiles/files/24246115260.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/lizibizijalepikaderumiru.pdfIn PDF document text
    • https://horacebatten.com/ckfinder/userfiles/files/zezofomobejitarux.pdfIn PDF document text
    • http://work4shop.cz/userfiles/file/musurusabajimopusif.pdfIn PDF document text
    • http://kemmurad.com/webroot/img/files/29180819795.pdfIn PDF document text
    • http://cuacuonnhaxuongbinhduong.com/upload/files/tonunez.pdfIn PDF document text
    • http://ilkconstruction.com/Images/Media/files/zigamaruro.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=fast+and+furious+1+download+720pPDF 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_off0000b410.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB410 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC22 16920 bytes
SHA-256: b54ce5526c2fd1ce73a8e7e900bcb999fb83b64f6d8d99f6e6511a214c563f3b
font_02_sfnt_off0000f801.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF801 10868 bytes
SHA-256: 8150c6a66ec4ba20f3f7016cc2b37f402d920b3eb9ad9e91d212092bd329c7bf