Malicious PDF — malware analysis report

Static analysis result for SHA-256 e785e1801b869ea1…

MALICIOUS

PDF

82.4 KB Created: 2021-09-20 08:08:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: f8a4d3cc0c563cd9071b1ddc3fea059b SHA-1: a65dd5910b6f11e761f5162c8c5ed60ad3ada5d9 SHA-256: e785e1801b869ea1b20485b89cbef00b61821cd76dc711ffa70ab973193098cb
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains numerous external links, many of which are hosted on disposable domains and appear to be part of a link farm. The PDF_RANDOM_URL_LINK heuristic specifically points to algorithmically generated URLs, suggesting an automated phishing or malware distribution scheme. No scripts were extracted, but the overall structure and heuristics indicate a phishing or malware lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 https://ketchas.ru/uplcv?utm_term=how+to+run+android+app+in+background PDF link annotation
    • http://voijin.com/userfiles/files/18654656565.pdfIn PDF document text
    • http://www.ettermanenterprises.com/ckfinder/userfiles/files/solileje.pdfIn PDF document text
    • http://grupopiscis.com/upload/files/25585797228.pdfIn PDF document text
    • https://www.funes.gob.ar/ckfinder/userfiles/files/dotigafibe.pdfIn PDF document text
    • http://ambulatorioveterinariobubiniregini.eu/userfiles/files/82759900995.pdfIn PDF document text
    • https://u15.ch/ckfinder/userfiles/files/wuwegur.pdfIn PDF document text
    • https://zoomkish.com/basefile/zoomkishcom/files/49919976671.pdfIn PDF document text
    • http://www.plain-pied.com/editeur/ckfinder/userfiles/files/85559691926.pdfIn PDF document text
    • http://pmke.cz/pictures/files/poguzepawezepi.pdfIn PDF document text
    • http://partner-support.net/user_data/userfiles/files/jozokugixufijibusev.pdfIn PDF document text
    • http://etabetasurvey.com/userfiles/files/mifuzu.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/fk1ginkg7k6h44l0o5f3kbav3c/rulagufatud.pdfIn PDF document text
    • http://olivetheater.com/userData/board/file/pitojepafat.pdfIn PDF document text
    • https://alate.org/admin/fckeditor/editorfile/bipezevevo.pdfIn PDF document text
    • http://jlsxjy.com/right/UploadFile/file///2021091118174173499.pdfIn PDF document text
    • http://www.chp.pl/ckfinder/userfiles/files/pijoruvaxowarire.pdfIn PDF document text
    • http://orosweb.hu/ckfinder/userfiles/files/zegejet.pdfIn PDF document text
    • http://thucphamchucnangmy.vn/uploads/files/86727468092.pdfIn PDF document text
    • https://oklogistic.lv/upload/file/pikaketubodokabot.pdfIn PDF document text
    • http://gpsputhuppally.com/userfiles/file/rokuvafirise.pdfIn PDF document text
    • http://centralcogtc.com/uploads/file/zuwuw.pdfIn PDF document text
    • https://g55net.com/webpagebuilder/ckfinder/userfiles/files/94585940283.pdfIn PDF document text
    • http://timnhanhonline.com/upload/files/visoradojunitawisoz.pdfIn PDF document text
    • http://dlevitin.ru/fck_editor_files/files/miwipanazajuxigug.pdfIn PDF document text
    • https://rjpexport.com/files/xorixi.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/ad5bc08bdac78ba202393e47c30d5c4e/datukedivarobop.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_off0000dd8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD8D 10752 bytes
SHA-256: 0406c5d2ad9998866fe4be9ee2dad3a34893516e21eda0e0e95c6d01e1a6af7c
font_01_sfnt_off0000f5f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5F1 17520 bytes
SHA-256: e4c89a059c7496d488b4a442ce8f47d418edea8c9179362d63c6e237d1db353b
font_02_sfnt_off00012389.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12389 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1