Malicious PDF — malware analysis report

Static analysis result for SHA-256 6f73bfe083282ef0…

MALICIOUS

PDF

70.5 KB Created: 2021-09-24 14:20:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5338c2dbbc23dc18b315cf11b03fc2f1 SHA-1: 4b575873421084c8cce98fd7189ec0c97cb099cd SHA-256: 6f73bfe083282ef08c462a9a97e7f640b3a20746709ab58b37ba64f84e54c71f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF was flagged by ClamAV and an ML classifier as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external PDF files hosted on various domains. The presence of numerous distinct hosts and the use of UTM parameters suggest an attempt at SEO poisoning or a similar traffic-generation scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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 http://cukiernia.eu/upload/files/somaresejosewizalokudajur.pdf In PDF document text
    • http://xn----7sbakn3aoflleitf3m6a.xn--p1ai/userfiles/file/7155559159.pdfIn PDF document text
    • http://rakkhunnursinghome.com/user_img/files/dowipudaneditabivum.pdfIn PDF document text
    • https://yptea.com/data/fckeditor/files/fipuxomipovanolukukoxome.pdfIn PDF document text
    • https://aljuboori.com/userfiles/files/bowamifiredezurawebu.pdfIn PDF document text
    • http://www.lovebliss.tw/UserFiles/files/58771736292.pdfIn PDF document text
    • https://www.wappa.com.au/siteadmin/ckfinder/userfiles/files/mavegozugaziduzid.pdfIn PDF document text
    • http://www.smartusb.info/images/library/File/82237533348.pdfIn PDF document text
    • https://senegal4d.com/contents/files/firirikuxewevilewopi.pdfIn PDF document text
    • https://cncunse.com/d/files/26785914622.pdfIn PDF document text
    • https://vozilasavozacem.rs/files/nafuxumesiro.pdfIn PDF document text
    • https://maryamghiasi.com/images/upload/files/jozutebabogimapa.pdfIn PDF document text
    • http://aallergy.friend-match.com/upload/files/21998061945.pdfIn PDF document text
    • https://taxforce.nl/userfiles/files/rupajivowozo.pdfIn PDF document text
    • https://sicurezzaips.it/uploads/file/31418945164.pdfIn PDF document text
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/fba6c532528dfcc22c5181a121191021/berepoperu.pdfIn PDF document text
    • http://dienlanhhuubinh.com/upload/files/80796970001.pdfIn PDF document text
    • https://tecnibat.net/uploads/archivos/62156161862.pdfIn PDF document text
    • http://sk-uralstroy.ru/uploads/files/76888112328.pdfIn PDF document text
    • https://safrano.pl/userfiles/file/vudavajibuwefoxup.pdfIn PDF document text
    • https://debcopharma.com/userfiles/file/dalusuvigolig.pdfIn PDF document text
    • http://jandenzobv.com/image_uploads/file/rozodiwejovamepebuteso.pdfIn PDF document text
    • http://gmkms.net/upfile_editor/2021/files/62187370858.pdfIn PDF document text
    • http://photo-preiss.com/upload_files/files/69789900318.pdfIn PDF document text
    • https://nepalonetours.com/userfiles/files/66837918094.pdfIn PDF document text
    • http://vertex-decor.com/userfiles/file/39413992775.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=saheed+esu+part+2PDF 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_off0000b21a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB21A 10420 bytes
SHA-256: 6bfd11f850de188ef42f9ae7bec0e6771e66d9a1d3fe4ba0729ad138d280e2c6
font_01_sfnt_off0000c9dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9DD 16600 bytes
SHA-256: 0d644e49d82f4eb2e3b6673d429e5d8b4c4665fc54f1a699c059053526e8391a
font_02_sfnt_off0000f471.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF471 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1