Malicious PDF — malware analysis report

Static analysis result for SHA-256 d21368158655dc1f…

MALICIOUS

PDF

87.9 KB Created: 2021-09-13 03:23:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 4a0601c237fad0431267ed9777af9190 SHA-1: 348af8e53e0b4523248edbc7f4c57bc939f81251 SHA-256: d21368158655dc1fb490b59d55131d405b6d659b9fdb22c4fe25c8fcde4f86e4
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. Heuristics indicate it functions as a link farm, directing users to multiple external PDF files hosted on various domains. While no scripts were directly extracted, the PDF structure and the presence of numerous external links suggest an intent to redirect users to malicious content, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://maslatalaia.com/userfiles/file/17872077734.pdf In PDF document text
    • http://only-svet.ru/upload/files/2732152313.pdfIn PDF document text
    • http://livelyway.com/ckfinder/userfiles/files/zekenulopono.pdfIn PDF document text
    • https://rajaunited.com/contents/files/loseluziwebukided.pdfIn PDF document text
    • http://rocb-ap.org/file_media/file_image/file/razutisesop.pdfIn PDF document text
    • https://batdongsandothanh.vn/luutru/files/wonimonoruwiwopipajufed.pdfIn PDF document text
    • https://autoroman-service.ro/imagini_ws/7738004658.pdfIn PDF document text
    • http://ekhoron21.mn/uploads/files/sibimorijawu.pdfIn PDF document text
    • http://whipitleather.com/userfiles/file/kixamitepobi.pdfIn PDF document text
    • http://brickchamber.com/ckfinder/userfiles/files/lesawi.pdfIn PDF document text
    • http://medtravel.pro/images/hand_uploaded/files/jerabinux.pdfIn PDF document text
    • https://sacc-la-chaux-de-fonds.ch/fichiers/file/80537366887.pdfIn PDF document text
    • http://teewer.mn/ckfinder/userfiles/files/51194965011.pdfIn PDF document text
    • http://silesiacapital.eu/data/file/51260465597.pdfIn PDF document text
    • http://khachsandomino.com/hinhanh_fckeditor/file/6373589966.pdfIn PDF document text
    • http://dangkykinhdoanhkiengiang.com/upload/ck/files/30113912422.pdfIn PDF document text
    • http://www.parinet.fi/tiedostot/files/58020680691.pdfIn PDF document text
    • https://hohsingfiber.com/ufiles/files/73702027343.pdfIn PDF document text
    • http://chuanghuilaw.com/filespath/files/20210901090349.pdfIn PDF document text
    • http://reszke.pl/fckeditor/editor/filemanager/connectors/php/file/lipawezisewunod.pdfIn PDF document text
    • http://poultech.net/d/files/26236186818.pdfIn PDF document text
    • https://blokhol.com/upload/files/lalurojipodirozazinotu.pdfIn PDF document text
    • http://kfbma.org/files/fck/file/bifuvotekasidukubudar.pdfIn PDF document text
    • http://topnotchimports.com/ckfinder/userfiles/files/8722094282.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=unturned+id+torchPDF 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_off0000f4b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010cca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CCA 18028 bytes
SHA-256: bd6ad4a674f6b8a4e432bf7f871d3d5692cd575a76b47f0811f2c47841e49b18
font_02_sfnt_off00013b6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B6E 10196 bytes
SHA-256: a5a151f70dbcf60d037387d80555c50c358675e09e2b42e1f705f223c3686bdd