Malicious PDF — malware analysis report

Static analysis result for SHA-256 a38646f624c396f9…

MALICIOUS

PDF

82.1 KB Created: 2021-09-19 07:05:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: fdf476e6ac445908c2faf885bf071f5a SHA-1: 76e08898fdb6d538c6454f663cc8303b223e8bc1 SHA-256: a38646f624c396f947c5a5c457af31917c3bc1213fe4d2151e2840c73a8dab4d
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 external URIs, many of which are hosted on disposable domains and utilize UTM parameters, suggesting a link farm or phishing lure. The presence of embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic further support this. While no scripts were explicitly extracted, the PDF structure itself likely facilitates the redirection to these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://queure.ru/uplcv?utm_term=minecraft+full+version+mod+apk PDF link annotation
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/5evpp9i1u6fomeji9h2sbqh4gv/40547581326.pdfIn PDF document text
    • http://imhome-listings.com/userfiles/files/96281636661.pdfIn PDF document text
    • http://gasthaus-steinkirchen.de/img/editor/file/gekefuleluguk.pdfIn PDF document text
    • http://e-store-sys.com/userfiles/file/tukiguzovuxaruguxuperoge.pdfIn PDF document text
    • https://deepex.hu/hirek/files/tudetuso.pdfIn PDF document text
    • https://gbp.dropship-online.com/userfiles/files/gexirezumepovinipi.pdfIn PDF document text
    • http://www.uds-myanmar.com/image/upload/File/tisufej.pdfIn PDF document text
    • https://techlan.pl/files/file/nosusekofenalidunakoju.pdfIn PDF document text
    • http://computer-rudolstadt.de/upload/file/tuvuzudumajobanaraf.pdfIn PDF document text
    • https://castilloexterior.org/ckfinder/userfiles/files/wusenofuvoxu.pdfIn PDF document text
    • http://kowel.com/ckfinder/userfiles/files/1630732808.pdfIn PDF document text
    • http://partnerplus30.ru/images/fornews/files/dafimuzatekiwagudi.pdfIn PDF document text
    • http://ilkyoukais.com/Images/Media/files/50990254011.pdfIn PDF document text
    • https://royal-art.pl/uploads/userfiles/files/95946634186.pdfIn PDF document text
    • http://recko.ru/ckfinder/userfiles/files/laxijedupupebupirimuzolez.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e64a479e85---sorekoxukeve.pdfIn PDF document text
    • https://pollackmihalyiskola.hu/ckfinder/userfiles/files/42741769287.pdfIn PDF document text
    • https://pamukoglu.com/userfiles/file/temumidorilozokira.pdfIn PDF document text
    • http://sovaimm.it/userfiles/files/wovat.pdfIn PDF document text
    • http://velo.hu/UserFiles/file/24737035571.pdfIn PDF document text
    • http://epmachine.ru/d/files/12559094805.pdfIn PDF document text
    • http://brilliantsolarpaneling.com/userfiles/file/68768258391.pdfIn PDF document text
    • http://www.primariasantana.ro/uploads/file/xerunuseduzabose.pdfIn PDF document text
    • https://dhesient.com/media/66091271339.pdfIn PDF document text
    • https://unimedbelem.com.br/painel_template/assets/global/plugins/ckfinder/userfilesfiles/63476594372.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_off0000d7ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7BA 11032 bytes
SHA-256: c4476e09751e2fd89938f0b257d7dd17c7cd0b069825ea8015a760f976fb634a
font_01_sfnt_off0000f16e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF16E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010980.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10980 19008 bytes
SHA-256: 2a22f96e89a0790c7444d5e313b20f8a3241a5106004d222f1cd3c15025281cd