Malicious PDF — malware analysis report

Static analysis result for SHA-256 87751972f66d5bd1…

MALICIOUS

PDF

77.5 KB Created: 2021-09-22 23:05:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 834005c59be49d3aa191e63b4ee6de7c SHA-1: f662b7fdc7e261d48f8fbda5a93d283c7a77da06 SHA-256: 87751972f66d5bd12580ee9c6dec971c9a9356f7afb0dded8360ecd809b472da
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, with one heuristic identifying it as a link farm on disposable hosting, suggesting a phishing or redirection scheme. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of an attempt to direct users to malicious sites, likely as part of a spearphishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9829

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://cpviettin.com/upload/files/49466981151.pdf In PDF document text
    • https://globalathena.com/ckfinder/userfiles/files/14233878242.pdfIn PDF document text
    • https://ehotelgateway.com/bot/ckfinder/uf/files/82065601702.pdfIn PDF document text
    • http://studio5r.com/userfiles/files/dezofabanalejukiniwof.pdfIn PDF document text
    • https://acgroupenterprise.com/userfiles/file/22878591023.pdfIn PDF document text
    • https://mmagame.com/userfiles/file/foxogerenenejup.pdfIn PDF document text
    • http://hoachathoanggia.com/userfiles/file/lezopud.pdfIn PDF document text
    • https://ncsccalgary.com/userfiles/files/pidosedonixi.pdfIn PDF document text
    • http://edeins.com/userfiles/file/10772393141.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/nrrs1opav01q3fdogh996m1r69/77503571925.pdfIn PDF document text
    • https://wonkingchina.com/d/files/lexirulivafevarufesoxomon.pdfIn PDF document text
    • https://thuanxuongmonmb.com/admin/webroot/upload/image/files/dajorowakemaxe.pdfIn PDF document text
    • http://inoxbienhoa.com/upload/files/lukebukubixowikubitujuxo.pdfIn PDF document text
    • http://daiichibus.vn/uploads/news_file/50303848653.pdfIn PDF document text
    • https://propactionvehiclesuk.tv/userfiles/files/54592393045.pdfIn PDF document text
    • http://pdww.ru/ckfinder/userfiles/files/60639760740.pdfIn PDF document text
    • http://kubablimel.pl/Image/files/54294651587.pdfIn PDF document text
    • http://www.tomasjelinek.com/img/pub/file/9548208532.pdfIn PDF document text
    • https://euronet.stonavka.cz/webpagebuilder/ckfinder/userfiles/files/61804884484.pdfIn PDF document text
    • https://www.iieng.org/editor/ckfinder/userfiles/files/66745970924.pdfIn PDF document text
    • http://tythb.com/uploadfile/files/40190806312.pdfIn PDF document text
    • https://rcvizovice.cz/ckfinder/userfiles/files/43417230716.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613d9bdfc1c1d---mikuxaruzezuwepejibewe.pdfIn PDF document text
    • https://maciejabramowicz.pl/upload/files/file/sasodesumapigikasume.pdfIn PDF document text
    • http://s-pack.kr/userfiles/file/20210908022849.pdfIn PDF document text
    • http://werder-ritter.de/UserFiles/File/rabirisuputujudesobowifak.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=how+to+cancel+a+text+message+on+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_off0000c9a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9A4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e1b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1B6 17836 bytes
SHA-256: d5c9dff4cd7fc26a65646f330ec564ab5d1730b667d813e7543e1d0c10bb548a
font_02_sfnt_off00010f22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F22 10892 bytes
SHA-256: 63196083ff808efa94199b6e7b3037eb04f2bbc6d6326939d1b9416fbd122079