Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a55137a6852123b…

MALICIOUS

PDF

71.9 KB Created: 2021-09-26 16:27:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9f78b8243c5fbdc022062d569d6e50cf SHA-1: 1581af909ddbb4ffb58b0e9614cedc8ea1eae157 SHA-256: 5a55137a6852123bb108d39e2a79a069171547ea774b536e1c385de32187c70f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ML and ClamAV as malicious, specifically as a phishing trojan. The PDF contains a large number of embedded links, many pointing to unknown or potentially malicious domains, consistent with a phishing or link farm attack pattern. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it's designed to redirect users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://kidneystonetreatment.in/userfiles/files/jiwalidixubafiwolebobasa.pdf
    • http://innospectrum.eu/hirlevel/file/57230792160.pdf
    • https://maharajganjtimes.com/assets/ckfinder/core/connector/php/uploads/files/xedofugosokifulu.pdf
    • http://arcenevents.nl/site/upload/files/70795458055.pdf
    • http://gartenbaukoeln.de/uploads/files/13222326326.pdf
    • http://spc1991.com/ckfinder/userfiles/files/51431364724.pdf
    • https://optical-axis.com/uploads/files/202109041732504238.pdf
    • http://orsini-blasioli.it/userfiles/files/misapirezufasatogefeboxut.pdf
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16131a5a6dc891---49117669285.pdf
    • http://rurisnet.org/images/file/15484982354.pdf
    • http://jamones-luna.shopcloud.es/ckfinder/userfiles/files/1497022414.pdf
    • http://cross-winds.in/upload/contents/images/images/mexisoti.pdf
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16131d7e165661---13201461670.pdf
    • https://majubesar.org/contents/files/rilaxob.pdf
    • http://bluebossa.pl/files/file/nurawamulegix.pdf
    • http://atya.eu/files/file/57813037502.pdf
    • http://carnavaldemarbella.com/Senegal_5/Content/files/userfiles/file/99137061768.pdf
    • https://igescanada.com/ckfinder/userfiles/files/9172883332.pdf
    • https://www.sherpachristain.org.np/ckfinder/userfiles/files/monitojurulof.pdf
    • http://www.benyowsky.com/resources/files/31849344080.pdf
    • http://iamsong.vn/uploads/files/16000494258.pdf
    • http://iproperty.ae/userfiles/file/manimidizapizunul.pdf
    • http://trungtinjsc.vn/upload/FCK/file/87234971743.pdf
    • http://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/6722904650.pdf
    • https://yocarbroker.com/upload/ckfinder/files/34145807242.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=how+to+wifi+tethering+android
    • https://tes-sys.com/uploads/ckfinder/files/20210925/16325203408173.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b784.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB784 16792 bytes
font_01_sfnt_off0000cf9b.bin
3d4ddcaad21f428a5e8664c233f176490bc10cdbd74bc07a019e089c9d05d76d
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF9B 10496 bytes
font_02_sfnt_off0000e73b.bin
c96195981e1106b89e79154b1042c39301552744b70acc101db8ecacab6c1de7
pdf-font-stream PDF embedded font (sfnt) at offset 0xE73B 16644 bytes