Malicious PDF — malware analysis report

Static analysis result for SHA-256 887dc11ef99c9230…

MALICIOUS

PDF

85.5 KB Created: 2021-09-17 15:43:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 624b9663352106c7a149067050bf2ff7 SHA-1: 5cba42e661c526f39115eadd3fa3f7d6f580909d SHA-256: 887dc11ef99c92309666747b515e8c874f2c4cc4ef6776738ee8ae44317b8e5d
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics as malicious, including a high-severity finding for random URL links and a critical ClamAV detection. The document body is heavily obfuscated, but the presence of numerous external links, many pointing to other PDF files on potentially disposable domains, suggests a link farm or distribution mechanism for malicious content. The ML classifier output of 0.997556 further supports the malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://donovaly-ubytovanie-safran.sk/web/userfiles/file/keliroror.pdf In PDF document text
    • http://librojuridico.com/aym_images/files/52430770057.pdfIn PDF document text
    • http://www.binghan.my/userfiles/file/xatomobimemiwagivorolize.pdfIn PDF document text
    • https://adeptos.clevercloud.pt/images/items/files/48726510040.pdfIn PDF document text
    • http://fishngrill.iorderfoods.com/uploads/files/70355744254.pdfIn PDF document text
    • http://ambulatorioveterinariopisillibertozzi.eu/userfiles/files/nepekevufavikilow.pdfIn PDF document text
    • https://chennothinterios.com/uploads/file/61250922263.pdfIn PDF document text
    • http://nbnjl.com/userfiles/files/43083151830.pdfIn PDF document text
    • https://gifarlcm.com/upfiles/editor/files/varozodujokas.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/xozodorexexenozojuwav.pdfIn PDF document text
    • https://responsible-tourism-alliance.com/content_file/files/75115865335.pdfIn PDF document text
    • http://tiyuchangdi.com/upload_files/files/20210907_081745.pdfIn PDF document text
    • http://dlabiura.kbo.pl/ckfinder/userfiles/files/lelupomuk.pdfIn PDF document text
    • http://www.dfdtrading.sk/ckfinder/userfiles/files/dafuta.pdfIn PDF document text
    • http://studioarclab.eu/userfiles/files/gejilogoparivuvorina.pdfIn PDF document text
    • http://brcassociati.com/userfiles/files/zigopuwufudid.pdfIn PDF document text
    • https://vasutaszeneiskola.hu/ckfinder/userfiles/files/gasoxofaverixixo.pdfIn PDF document text
    • http://jocoseatee.com/userfiles/files/97379903894.pdfIn PDF document text
    • https://rosebankprimary.co.za/inc/ckfinder/userfiles/files/derarubovafadafigil.pdfIn PDF document text
    • https://kiptep.ru/file/fiwukavojotuzusu.pdfIn PDF document text
    • http://logo4you.dk/userfiles/file/93492114599.pdfIn PDF document text
    • https://penzion-pod-rozhlednou.cz/img/file/89439787588.pdfIn PDF document text
    • http://eggtesting.com/admin/uploads/file/65322625771.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=why+is+android+phone+not+connecting+to+wifiPDF 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_off0000e866.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE866 11044 bytes
SHA-256: 0679121159bb60c15db7b0f473621b8c85667ab3f72397fe24333929e45ea858
font_01_sfnt_off000101f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011a03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A03 17656 bytes
SHA-256: 28a641c33d27cb7de96af6e2700020acd31b60a84fba1d7e17d905cf72c434e7