Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7cbb421325fa57a…

MALICIOUS

PDF

74.9 KB Created: 2021-09-27 09:27:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3dfc5c2187e3a0bd2fd01f831da40e58 SHA-1: ca15db40ad0de676277ecb4ccd66d65cc6a7ef88 SHA-256: b7cbb421325fa57a59e24103fe1a881ad9fde7911ea11e0a9cd372774acedd28
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document is designed as a link farm on disposable hosting, with numerous embedded URLs pointing to potentially malicious content. The presence of external URIs and the overall structure suggest an attempt to redirect users to phishing or malware download sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://oniceh.ru/uplcv?utm_term=download+game+gta+sa+android+gratis PDF link annotation
    • http://riskhedgetech.com/uploaded/file/5501002156149d7bc5d6cc.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161483b94165c5---23450701008.pdfIn PDF document text
    • http://chamdure.com/DATA/files/36760314705.pdfIn PDF document text
    • http://quiltingacademy.info/fckeditor/userfiles/file/52296993255.pdfIn PDF document text
    • http://hzeiger.com/userfiles/file/porevidodub.pdfIn PDF document text
    • http://musicincw.com/fckeditor/userfiles/image/voxefavijarunita.pdfIn PDF document text
    • https://cultureresortpokhara.com/assets/userfiles/files/limixewavaleg.pdfIn PDF document text
    • https://cgeminfos.ma/upload/file/52284353113.pdfIn PDF document text
    • http://www.eurosecurimed.com/ckfinder/userfiles/files/51787024169.pdfIn PDF document text
    • https://www.xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/43908133222.pdfIn PDF document text
    • http://ros.by/ckfinder/userfiles/files/tesosaluzolesesagatujo.pdfIn PDF document text
    • http://numere-mopede.ro/mm/file/56805164552.pdfIn PDF document text
    • https://fablab808.com/nbloom/fckuploads/file/varomotuze.pdfIn PDF document text
    • http://kbautotech.com/board/datafiles/imagefile/jomesosuga.pdfIn PDF document text
    • https://markmont.eu/editor_uploads/system/files/46443978848.pdfIn PDF document text
    • http://kcemsp.org/upload/editor/file/31240479973.pdfIn PDF document text
    • http://excitechem.com/userfiles/file/mivuposibufopiwawapuxi.pdfIn PDF document text
    • http://knowleangling.co.uk/ckfinder/userfiles/files/lamozidusutagexo.pdfIn PDF document text
    • https://kocarbonag.com/luutru/files/96698567036.pdfIn PDF document text
    • http://101-games.ru/images/uploads/files/25413085976.pdfIn PDF document text
    • https://hatinhjobs.com/upload/files/jesorefegumafaloj.pdfIn PDF document text
    • http://yuemeism.com/uploadfiles/files/6419950226.pdfIn PDF document text
    • http://sushiosushi.com/uploads/files/57820823774.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_off0000ba75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA75 10680 bytes
SHA-256: 0e747b39a7c4d36498d2a36f7603732439568c0500e6172e4f965ab84378a175
font_01_sfnt_off0000d2c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2C5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ead7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD7 19752 bytes
SHA-256: 4f78157904f97618547037d219457f20d8f77c28a95afd42ebbc5035924c770f