Malicious PDF — malware analysis report

Static analysis result for SHA-256 8aca0d119fc79cce…

MALICIOUS

PDF

69.0 KB Created: 2021-09-26 16:24:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 539c2da27db0d5c5fe29788ddc5ca3bb SHA-1: e3e1b0cf8d77025350eb2683163e1f05ab50a0d5 SHA-256: 8aca0d119fc79ccef3d6aac34785f8f92b3471b237dc7b6213fd9d53513f3637
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable domains, and one heuristic identified it as a link farm. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 http://niengrangchuyensau.com/upload/contentFile/file/34277755991.pdf In PDF document text
    • http://wmasgroup.com/userfiles/file/zixut.pdfIn PDF document text
    • http://xn----7sbbgprpk7biiq.xn--p1ai/admin/ckfinder/userfiles/files/xesubegubijivitepaluse.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///20210926112538_1007696673.pdfIn PDF document text
    • https://mitrasuksesku.com/userfiles/file/39695268655.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1612f26ac112b2---kurowibirafatipavikovew.pdfIn PDF document text
    • http://perevodvnegiloifond.ru/pict/file/rilulibidezofapiwer.pdfIn PDF document text
    • http://jandebruijn.com/uploadimages/files/42794397779.pdfIn PDF document text
    • https://matricula.netlandschool.cl/files/lufegopuvimojirilapukor.pdfIn PDF document text
    • http://webcertain.net/contentupload/fckeditorUploads/organization_/file/fewuvoxutexuwidategorup.pdfIn PDF document text
    • http://robertoantoniz.com/resources/original/file/vuwivegefun.pdfIn PDF document text
    • https://pharma-tools.eu/galeria/file/sozod.pdfIn PDF document text
    • http://okna-kurska.ru/page_edit/_samples/userfiles/files/komiromowamobidovuxefodit.pdfIn PDF document text
    • http://tweddlefoto.com/files_contenidos/upload/files/lerugilogozagokaxevigap.pdfIn PDF document text
    • http://taihegas.com/filespath/files/20210910232725.pdfIn PDF document text
    • http://pujcovnanaradi-tvarozna.cz/userfiles/files/lomivago.pdfIn PDF document text
    • http://neza.cz/UserFiles/File/33386359802.pdfIn PDF document text
    • https://businessincasey.com.au/application/third_party/ckfinder/userfiles/files/30754925302.pdfIn PDF document text
    • http://www.siposferenc.hu/html/63394790461.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161377c2e1dcbb---pajimexulaxite.pdfIn PDF document text
    • http://www.bash.cl/media/file/kupedajuxokarad.pdfIn PDF document text
    • https://ziyang100.com/userfiles/file/art_16320116255879.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=how+to+transition+from+iphone+to+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_off0000b180.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB180 14812 bytes
SHA-256: 7e4922ce761d8e47e7536627c993871183c4b1405f60f0a923d0bd94977e69f5
font_01_sfnt_off0000d583.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD583 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ed9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED9A 10792 bytes
SHA-256: 3a793b5a846fb64547061a34f27407b8b1e6fa695562e73ada405dccb7356978