Malicious PDF — malware analysis report

Static analysis result for SHA-256 a438c99665de7764…

MALICIOUS

PDF

76.3 KB Created: 2021-09-15 14:58:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: e5f204534770b760e9d21feac789a4b8 SHA-1: 9e62dfef286c37fd23fe96753eb1db5e38e9849c SHA-256: a438c99665de7764099694c5ebd2370304c9f41d2beb823eff097911cfe6e5f1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting, suggesting an attempt to distribute malicious content or engage in SEO manipulation. No scripts were extracted, but the overall structure and URL patterns indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 http://kirakuramen.com/uploads/files/bobugeruvudulovasadonen.pdf In PDF document text
    • http://fbrasil.com/userfiles/file///mabolagewifavipixagid.pdfIn PDF document text
    • https://adikkeempat.com/contents/files/47915382127.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137e18185b29---2889394581.pdfIn PDF document text
    • http://nprofit.hk/userfiles/76394133280.pdfIn PDF document text
    • http://imobilestore.de/userfiles/file/lotumawabajamululiled.pdfIn PDF document text
    • http://icsbc.ru/fuploader/file/jakugixujuvefuxujizuzav.pdfIn PDF document text
    • http://lica-mpt.it/userfiles/files/xokovoxitire.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/1613bea7b9449e---34808085472.pdfIn PDF document text
    • https://www.jnvhardoi.org/ckfinder/userfiles/files/fisetazi.pdfIn PDF document text
    • http://kommunikator.nu/demo/userfiles/file///falowizevebamerudolase.pdfIn PDF document text
    • https://k-barrierfree.com/FileData/ckfinder/files/20210903_9F8F77E51F4B33E6.pdfIn PDF document text
    • http://www.addvanceo.info/userfiles/files/69494227047.pdfIn PDF document text
    • https://gres-k.cat/userfiles/file/42492491972.pdfIn PDF document text
    • http://pensjonatagat.pl/userfiles/file/69397535224.pdfIn PDF document text
    • https://zivotzaokny.eu/res/file/niragunuxolafeloku.pdfIn PDF document text
    • http://fireprovietnam.net/luutru/files/24691332686.pdfIn PDF document text
    • http://bigyikesmedia.com/home/xtremweb/public_html/consultinstitute/web/upload/files/11662798510.pdfIn PDF document text
    • http://diskacme.dk/images/upload/file/15302130482.pdfIn PDF document text
    • http://stonebreaker.at/14226828290.pdfIn PDF document text
    • http://yishiweb.com/upfiles/files/20210902_080414.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/9ed5e0ef8460b2b9cd38239ae6058f75/12416015036.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=use+of+carrier+services+in+androidPDF 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_off0000c6df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6DF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000def1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEF1 17500 bytes
SHA-256: b1c10d261be9127a3e78bb882534844b1f31611aa0fb0196ad64b710eff01a6c
font_02_sfnt_off00010c7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C7A 10400 bytes
SHA-256: 55814b9443d4d9d3d6176817d130d819a86d2c90e95e486f3d28d3641652b496