Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c913d142564367a…

MALICIOUS

PDF

81.5 KB Created: 2021-09-13 09:17:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 47ad5922d603b105580dfaef3a6cca30 SHA-1: 292216891cbc39f728c90e4c6d48a57f2debeb8c SHA-256: 1c913d142564367a30c93e9916d640e6756eefea252d2344eb7629259f3ba451
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable hosting and form a link farm, a common tactic for phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and the presence of numerous external links suggest an attempt to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://cjsc.se/ckfinder/userfiles/files/lekunegamawavo.pdf In PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/c7abd7089385d8ce536c61d627817ade/jiwupinugilodijatimiwi.pdfIn PDF document text
    • https://www.mnogotrop.com/ckfinder/userfiles/files/57272569948.pdfIn PDF document text
    • http://sinocelltech.com/filespath/files/20210910185306.pdfIn PDF document text
    • http://ranjitabiswas.com/userfiles/files/71214713844.pdfIn PDF document text
    • http://coyada.com/up_images/up_images/tulapaweboxawavofogipopor.pdfIn PDF document text
    • http://philboyd.com/19456813224.pdfIn PDF document text
    • https://alienaquatics.com/home/gb/public_html/ckfinder/userfiles/files/wedeveduzabusobenuv.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/tokuvubov.pdfIn PDF document text
    • http://netisiletisim.com/guvennet/resimlerfiles/jijeke.pdfIn PDF document text
    • http://mamnonsaokhue.vn/app/webroot/files/ckfinder/files/nugeza.pdfIn PDF document text
    • https://littleedupark.com/ckfinder/userfiles/files/20124742917.pdfIn PDF document text
    • http://kukubara.com/zdjecia/file/86532434616.pdfIn PDF document text
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/359d4c0cd0cd29a57efbcecdb77e4006/loziruba.pdfIn PDF document text
    • http://1666-3668.com/attach/userfiles/file/xexen.pdfIn PDF document text
    • http://irths.com/upload_files/files/94938793407.pdfIn PDF document text
    • http://hoanhaochemical.com/uploads/files/44247361001.pdfIn PDF document text
    • https://balbok.net/admin/ckfinder/userfiles/files/kedulaxuvoko.pdfIn PDF document text
    • http://borik.customreal.sk/data/files/xugopabavedijibegenole.pdfIn PDF document text
    • http://identik.hu/editor_up/33829763658.pdfIn PDF document text
    • https://www.playitdirect.ca/ckfinder/uploadfiles/files/dopewigebigi.pdfIn PDF document text
    • http://duda-tech.pl/dudatech/upload/file/69930985839.pdfIn PDF document text
    • https://milliondollardesiclub.com/upload_files/featured/files/fezirumoveber.pdfIn PDF document text
    • https://ka-base.no/images_content/file/44791094124.pdfIn PDF document text
    • http://www.cafeinca.com/img/public/contenido/file/supowabamupaneziwuvatol.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+screenshot+on+android+11PDF 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_off0000d541.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD541 19384 bytes
SHA-256: 61cb24432609814cb4b84e4bb5c78bea606d7cad7152e93f6e2975b2e1ab3835
font_01_sfnt_off000107a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107A3 10552 bytes
SHA-256: 97fb1d784ad9dae2e84ea82ddc24571d50f31dcb0b1e9a8a57145e0e43c64167
font_02_sfnt_off00011fba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FBA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1