Malicious PDF — malware analysis report

Static analysis result for SHA-256 82cff4a74a682563…

MALICIOUS

PDF

69.8 KB Created: 2021-10-02 22:16:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: f444d485383eb773070619b6f0cc9847 SHA-1: cdb8a83a473e0a0b2e59425ccdc7b71d5347aea4 SHA-256: 82cff4a74a682563bc10ede4e311b425050c1466362a8fe42785bf851270ad5f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and is identified as a link farm on disposable hosting, suggesting it's used to redirect users to potentially harmful sites. The PDF structure and embedded URLs point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 https://krisoc.ru/uplcv?utm_term=external+influences+meaning PDF link annotation
    • http://surveycook.com/upload/tmp/202109/file/96366307754.pdfIn PDF document text
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/kafoxunelovavosivu.pdfIn PDF document text
    • http://fasson.vip/images/editor/files/26267159122.pdfIn PDF document text
    • http://sostrevalli.it/userfiles/files/watitaxipuva.pdfIn PDF document text
    • https://campfun.myhost888.com/upload/ckeditor/files/16316653213.pdfIn PDF document text
    • https://www.karelo.com/uploads/File/gawosafapoperikobaduj.pdfIn PDF document text
    • http://nsdadventist.org/FCKData/file/93776822306.pdfIn PDF document text
    • https://kitchensofdiablo.com/upload/file/84038139243.pdfIn PDF document text
    • http://321eastern-thailand.com/userfiles/files/76278671929.pdfIn PDF document text
    • http://highendschmiede.de/highendfiles/file/60023891356.pdfIn PDF document text
    • https://drlanda.hu/user/file/fitekuwowudimigarok.pdfIn PDF document text
    • http://thedewakohchang.com/image/upload/File/6779710765.pdfIn PDF document text
    • http://hwangtosidae.com/userData/ebizro_board/file/51926748675.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/16150b4f32ed82---59503622341.pdfIn PDF document text
    • http://bladensburg.abwingsmd.com/uploads/files/76380878054.pdfIn PDF document text
    • http://swvocal.com/data/se2/file/83669784798.pdfIn PDF document text
    • https://mogilew.ru/userfiles/file/62627310349.pdfIn PDF document text
    • http://szjwwj.com/userfiles/file///45520687265.pdfIn PDF document text
    • https://cupanghitam.com/contents/files/ranumebotasosujixokotag.pdfIn PDF document text
    • http://phukhoabacninh.com/images/files/49212297045.pdfIn PDF document text
    • http://eortak.com/img/fck_temp/file/pifurizuraluvolirasuza.pdfIn PDF document text
    • http://newtrichur.com/userfiles/file/30657794341.pdfIn PDF document text
    • http://qamsar.org/userfiles/files/mikiguwabigu.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/341tbrq27h6vk2t19pcuh7ne02/59549819544.pdfIn PDF document text
    • http://ayrh.internet-match.com/upload/files/siwulaxinupi.pdfIn PDF document text
    • 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_off0000b0e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0E3 10744 bytes
SHA-256: b6bfe6a2130c15e5c123b211e3aa3f389d6833f6275074f63d847520f8050df0
font_01_sfnt_off0000c990.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC990 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e1a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1A2 15748 bytes
SHA-256: 08c03b23934be40271e22e2691d9393d1c355b90ac18d9d9fbee01a94771197e