Malicious PDF — malware analysis report

Static analysis result for SHA-256 eac6424e88e96a2e…

MALICIOUS

PDF

69.9 KB Created: 2021-09-24 23:30:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7a91d91e60e5a7d62d496801524146a6 SHA-1: a360c83defe532c384526b99a25760818de4eee8 SHA-256: eac6424e88e96a2efb124ea8a6964aca07394f981a185c31d4944e170aae6a03
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV and a machine learning classifier as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, hosting numerous links to disposable domains, with one prominent URL being https://krisoc.ru/uplcv?utm_term=advanced+fighting+fantasy+2e. The document body is heavily obfuscated, preventing a clear understanding of its direct content, but the overall structure and URL distribution strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://krisoc.ru/uplcv?utm_term=advanced+fighting+fantasy+2e PDF link annotation
    • http://miyagi.chi-kara.net/Upload/files/75265747493.pdfIn PDF document text
    • http://zhhyhb.com/uploadfiles/files/38058879069.pdfIn PDF document text
    • https://pomacanthe-art.fr/imagebeforeafter/files/baluvaj.pdfIn PDF document text
    • http://toptoptraining.ru/img/upload/file/zosapugegasinaxopizeze.pdfIn PDF document text
    • http://studiogiamberardino.it/userfiles/files/losetavebifatojenovus.pdfIn PDF document text
    • https://franchisebusinessadvisors.franchisebrokerwebsites.com/broker-site/files/files/61013967998.pdfIn PDF document text
    • https://curewelldiabetes.com/userfiles/file/88090664703.pdfIn PDF document text
    • http://digitalpolicycouncil.org/imagenes/file/77392825448.pdfIn PDF document text
    • https://ezsprinting.com/userfiles/file/womadubizazudu.pdfIn PDF document text
    • http://chipgene.com/image/files/20210913_005641.pdfIn PDF document text
    • https://monyetmesum.com/contents/files/worug.pdfIn PDF document text
    • http://obraz-tlt.ru/userfiles/file/4718131859.pdfIn PDF document text
    • http://smsalumni1971.com/apadmin/uploads/userfiles/files/7719200998.pdfIn PDF document text
    • http://fabiocaronearchitetto.com/userfiles/files/zidazokuranubakulipufive.pdfIn PDF document text
    • https://saleskerala.com/ckfinder/userfiles/files/godef.pdfIn PDF document text
    • http://donaldnathanlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/texopanowebivedusigita.pdfIn PDF document text
    • http://www.sosonomo.com/ckfinder/userfiles/files/fewimosisewutomil.pdfIn PDF document text
    • https://jechrina.gr/FCKeditor/userimages/file/74770461697.pdfIn PDF document text
    • http://lepetitjaunais.com/userfiles/file/tamakajugitujitutitabawog.pdfIn PDF document text
    • https://inprovituruguay.com/ckfinder/userfiles/files/wafupo.pdfIn PDF document text
    • https://reparationmobile.net/userfiles/file/kopodosuletorusonexetewo.pdfIn PDF document text
    • http://icmasistemas.com/userfiles/files/3017732764.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_off0000b047.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB047 16000 bytes
SHA-256: 86c7b8c66308454b257737cc4205928119a1c23447892d33609eed0eaf4e3751
font_01_sfnt_off0000d8e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8E7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f0fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0FE 10768 bytes
SHA-256: ead4d08189a9b2146e8759a4c442dbd46eb4c1af65d33e669e6ec51ee41ebcbc