Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8c40813e61d4ac5…

MALICIOUS

PDF

86.4 KB Created: 2021-09-18 07:21:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ac0522001ae141b66ad379ebc4606627 SHA-1: 5d3a6f76e9ee14cc369e74c67b242a63dee4937a SHA-256: a8c40813e61d4ac53ffd050da046f55abbf1b36228ad9658ab3148ce4a503d69
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to other PDF files, suggesting a link farm or a phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a phishing or SEO manipulation attack, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://donateagift.eu/userfiles/file/mudovagizanijubetif.pdf In PDF document text
    • https://burlingame.com/wysiwygfiles/file/genajilufononuvuda.pdfIn PDF document text
    • http://netinflux.net/userfiles/file/37185329638.pdfIn PDF document text
    • https://faresaldabbous.com/uploads/file/96193113545.pdfIn PDF document text
    • http://plymouth-logs.co.uk/ckfinder/userfiles/files/misexitutiwufawun.pdfIn PDF document text
    • http://brezov-gaj.si/uporabnik/file/1138991040.pdfIn PDF document text
    • http://nhatminhtrading.vn/app/webroot/uploads/files/kovonisazomube.pdfIn PDF document text
    • http://parcroyale.hk/userfiles/dusovivapanubowaxavaxer.pdfIn PDF document text
    • http://xn--elementy-zczne-kwb98g.pl/media/file/37945075957.pdfIn PDF document text
    • https://lomasdelaweb.com/userfiles/2008.09/file/litesoxilunesifodudike.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/4420987964.pdfIn PDF document text
    • http://autoklej.pl/app/webroot/media/files/87490581999.pdfIn PDF document text
    • https://coil.hk/upload/files/manemevolizanire.pdfIn PDF document text
    • http://gajagotour.com/UserFiles/file/gunufinizezazago.pdfIn PDF document text
    • https://menuiserie-sainte-anne.fr/userfiles/file/xosisixerada.pdfIn PDF document text
    • https://treasurehunterdetectors.solar-ovens.net/ckfinder/userfiles/files/zebopezobirikisilibubire.pdfIn PDF document text
    • http://mateuszkucharski.pl/admin/file/51454369061.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/161438d8f61d0a---94052847141.pdfIn PDF document text
    • https://zzwgjx.com/d/files/36212888016.pdfIn PDF document text
    • http://stuarteisbrucklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/wonudafirutunokap.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135418b23e2a---39586634832.pdfIn PDF document text
    • http://geonatlife.es/ckfinder/userfiles/files/gotisimixopipevujuxesanez.pdfIn PDF document text
    • https://kcharp.com/ckfinder/userfiles/files/damefasesubifovuzisikuz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=red+dragon+thomas+harris+pdfPDF 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_off0000e6ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6EF 10944 bytes
SHA-256: 63339bb67dea65557e0533243aff52d8b5b34906c6e92c849d83d51ef3a71c55
font_01_sfnt_off0000ffdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFDF 19864 bytes
SHA-256: f8ae2373fd10e1094bca7f152be43031b8ea76df2958656a91b63bf8f06c23c9
font_02_sfnt_off00013400.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13400 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1