Malicious PDF — malware analysis report

Static analysis result for SHA-256 cacb34a6e4721f22…

MALICIOUS

PDF

70.4 KB Created: 2021-10-04 09:35:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f52dc0fca71ba70ab87c0bb03b510967 SHA-1: fc678a470fcdd753b5e181b61087eb6e2523d4f7 SHA-256: cacb34a6e4721f22dccd309575066a28602b99f9325ccda917687c342718e29e
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. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document contains numerous links to disposable hosting, suggesting a phishing or malware distribution scheme. The embedded URLs further support this, pointing to various PDF files on potentially untrusted domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 https://chcial.ru/uplcv?utm_term=non+surgical+treatment+of+mucocele PDF link annotation
    • http://gibisch.biz/files/files/74488316891.pdfIn PDF document text
    • http://neoneofitou.com/ckfinder/userfiles/files/97732948539.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614f2349808d1---72635378783.pdfIn PDF document text
    • http://parfumerieindex.nl/images/uploads/miruvaza.pdfIn PDF document text
    • http://everestlodgelukla.com/userfiles/file/79867331197.pdfIn PDF document text
    • http://xn----itbbfrdrdbd4bgy6gi.xn--p1ai/webroot/files/files/dogaxigaxurefipuja.pdfIn PDF document text
    • http://acmemask.com/upfiles/editor/files/8973440374.pdfIn PDF document text
    • http://zekejozsef.eu/FCKfeltoltott/file/teduli.pdfIn PDF document text
    • https://ntpuvoice.com/ckfinder/userfiles/files/63785576689.pdfIn PDF document text
    • https://www.ksmt.edu.np/assets/ckfinder/userfiles/files/bepusuzeva.pdfIn PDF document text
    • http://jn-zhsc.com/upload/21684284973.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/zodukanugijerakititi.pdfIn PDF document text
    • http://tranhdaquydep.vn/upload/files/vosilipodute.pdfIn PDF document text
    • http://php-lounge.de/userfiles/file/9885104153.pdfIn PDF document text
    • http://kiko168.com/UploadFile/file/20210907094908946.pdfIn PDF document text
    • https://kotata-zlin.cz/obr/clanky/file/34783072200.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/e99914c5a32665ba8399b2d3bac2eb14/16058915312.pdfIn PDF document text
    • https://rovetco.com/userfiles/file/56820721749.pdfIn PDF document text
    • https://santaclara.com/wysiwygfiles/file/96121287663.pdfIn PDF document text
    • https://lufty.cz/UserFiles/files/1655851243.pdfIn PDF document text
    • https://stancijanegrin.com/UserFiles/files/mufufarozojokuxizefavagib.pdfIn PDF document text
    • https://mylin.in/ckeditor/ckfinder/userfiles/files/44878988774.pdfIn PDF document text
    • https://geloracinta.com/contents/files/bisomug.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_off0000b123.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB123 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c935.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC935 16336 bytes
SHA-256: 5f2e78e79a62ff7f1872b59b3931b6aa2b6a2eaf74079553a208d88b979c3c0a
font_02_sfnt_off0000f320.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF320 10756 bytes
SHA-256: 109e87ebc6929bc68d0d5f1adf6c7b64c6394664fe87a91e1c764d057d092ab7