Malicious PDF — malware analysis report

Static analysis result for SHA-256 823957d1b1cc47fd…

MALICIOUS

PDF

69.9 KB Created: 2021-09-29 01:01:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: f74b000799a0746daceca201fd3fd0a9 SHA-1: b9877cd768bee93ee96c5f018575bedbc7d5a3f4 SHA-256: 823957d1b1cc47fdef42dd6bea3b74c2b3ff47521a92f043449f27f793783879
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links pointing to external websites, many of which are hosted on disposable domains or compromised CMS uploads, suggesting a link farm or phishing lure. The PDF structure itself is also noted as potentially compromised, with duplicate object bodies.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9959

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://tion.hu/upload/file/60945241432.pdf In PDF document text
    • https://sakura-bashi.com/uploads/files/202109230757009220.pdfIn PDF document text
    • https://inwestorfinanse.pl/userfiles/file/62097287753.pdfIn PDF document text
    • http://stmarysharipad.com/userfiles/file/jikixutalasubada.pdfIn PDF document text
    • http://tentimesneedlehill.com/UPFILE/userfiles/files/88126998584.pdfIn PDF document text
    • https://vnnc.vn/img-hdmedia/files/64880302077.pdfIn PDF document text
    • https://www.pension-chevaux-haras-gabereau.fr/ckfinder/userfiles/files/nasolebitekofa.pdfIn PDF document text
    • https://hardlineconstruct.ro/app/webroot/files/userfiles/files/43806987331.pdfIn PDF document text
    • https://comptables-publics.fr/userfiles/file/1626009571.pdfIn PDF document text
    • https://rabudiagnostic.com/userfiles/files/33428241002.pdfIn PDF document text
    • http://villalapinetafavignana.it/userfiles/files/79439789454.pdfIn PDF document text
    • https://protectname.xyz/whoisprivacy/userfiles/files/46285206313.pdfIn PDF document text
    • http://www.alfapilates.pl/upload/file/fonagen.pdfIn PDF document text
    • http://pate4me.com/userfiles/file/37478292405.pdfIn PDF document text
    • http://gamboeng.com/assets/ckfinder/userfiles/files/vadenipini.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/16136f2ce45ded---nawelapopadejowofazos.pdfIn PDF document text
    • https://rayvoltbike.tw/geektic/files/73998637227.pdfIn PDF document text
    • https://tarzminder.com/resimler/files/fepekusiloraduzil.pdfIn PDF document text
    • http://pretaporter-pegah.com/userfiles/file/90002193425.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16133ff505ee9e---xejilesoloxuloxixa.pdfIn PDF document text
    • https://giasidaily.com/uploads/userfiles/file/34837828607.pdfIn PDF document text
    • https://dom4m.lv/userfiles/files/weluwoxebemoduzowimabaruv.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16131fd7b0f83e---81067473420.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=game+of+thrones+season+8+episode+7+full+episodePDF 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_off0000aece.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAECE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c6e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6E5 11160 bytes
SHA-256: 2f58f6642b88db7c2288e704a1a7e63b89ab4d2a56f94876fe450f19986b3c57
font_02_sfnt_off0000e0d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0D5 15480 bytes
SHA-256: 76a8974c29b81b0af6b0c20d517ce036fbaebb0d6673ef30af20fbf8cf85d7bd