Malicious PDF — malware analysis report

Static analysis result for SHA-256 c838d51f4b62756c…

MALICIOUS

PDF

74.5 KB Created: 2021-09-18 08:00:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: b903055beff189998d4afe3f54ba301d SHA-1: c77e8c4f665a721b85508cae59cb3613e53a9033 SHA-256: c838d51f4b62756c62142952e86719a5f8137182c4bcde1019eba4cdf5ab97a5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by multiple heuristics and a machine learning classifier as malicious. It contains numerous external URIs and links to compromised CMS upload storage, indicating a link farm designed to redirect users to potentially malicious sites. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports its malicious nature. No scripts were extracted, but the PDF structure and URL patterns suggest it is used for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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 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 https://philabc.ru/uplcv?utm_term=the+force+theme+piano+sheets+free PDF link annotation
    • https://apartmani-mestrovic-krk.hr/files/gapagebogasoladapado.pdfIn PDF document text
    • https://gym-rectif.fr/ckfinder/userfiles/files/ragefemivipifinoteneni.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/311eqdgd2b5r1lect3nf0cbj0k/kepulisoxorowila.pdfIn PDF document text
    • http://novo-foto.ru/ckfinder/userfiles/files/lutivowalu.pdfIn PDF document text
    • http://gyogytornasz.hu/editor_up/25858335005.pdfIn PDF document text
    • http://gsemilia.it/userfiles/files/wepag.pdfIn PDF document text
    • http://physio-praxismitte.de/userfiles/vuvuparitofo.pdfIn PDF document text
    • http://chiangmai-esc.net/user_img/files/zumanipiribo.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16140147281deb---16506183778.pdfIn PDF document text
    • http://goodmax.ru/i/files/moxebifobit.pdfIn PDF document text
    • http://transbur.ru/admin/ckfinder/userfiles/files/xokelezekoponabebemumuze.pdfIn PDF document text
    • http://ksiclubbiz.ksiclub.org/svnprojects/DHD/Source/images/files/zejodokapupolezu.pdfIn PDF document text
    • http://www.bash.cl/media/file/zuxilazitezonudufotu.pdfIn PDF document text
    • http://mbjarrahi.com/UploadedFiles/New/file/jewekateli.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/84fb6ogspmul457uemmn0fjenv/kewejezip.pdfIn PDF document text
    • http://dobryremont.pl/ebobas/portal/app/webroot/img/tmp/file/16310337266761.pdfIn PDF document text
    • https://al-farh-iq.com/upload/userfiles/file/85048873034.pdfIn PDF document text
    • http://studiotecnicoprato.eu/userfiles/files/befizal.pdfIn PDF document text
    • http://myphamlulanjina.com/upload/files/bizetot.pdfIn PDF document text
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/ee5aac915edfe5afd4185ef7879b3b97/pafasatuzeg.pdfIn PDF document text
    • https://vozilasavozacem.rs/files/zerefotitibavopawame.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_off0000b5e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5E9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cdfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDFB 20732 bytes
SHA-256: 256d377729df7e87f0af789f2ae3bdec6bd179ee99cc41fa991f6a49129a4d5e
font_02_sfnt_off00010268.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10268 10664 bytes
SHA-256: d86540dd6af32becf3826ffe302a68dabb819a7094ade23373ba3f33440686d4