Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4a1561ddc2e66e8…

MALICIOUS

PDF

76.6 KB Created: 2021-10-14 12:58:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ae923b077051e95c8e085e34dd4728bd SHA-1: 5a5cef7b40bb85fc76341757f95f0822b8dac4de SHA-256: a4a1561ddc2e66e810bf6df3dafbd3313c233dc5f3eb53b77db4a8a21aa12420
156 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 links to external websites, many of which are hosted on disposable domains or compromised CMS uploads, indicating a link farm designed to redirect users to malicious content. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://oniceh.ru/uplcv?utm_term=bus+duct+installation+manual PDF link annotation
    • http://akvari-um.ru/userfiles/file/36267107999.pdfIn PDF document text
    • https://marjoyunlar.com/calisma2/files/uploads/75589461307.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1615db0bace096---91403470661.pdfIn PDF document text
    • http://speednewslive24.com/assets/ckfinder/core/connector/php/uploads/files/29142643680.pdfIn PDF document text
    • http://woodlandhills.ilovepokebar.com/uploads/files/dukuxetekexiru.pdfIn PDF document text
    • http://smarttechsolutionukltd.com/uploaded_files/userfiles/files/44757549619.pdfIn PDF document text
    • http://hublihorse.com/uploads/userfiles/files/43581473985.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615c4ec638a28---vojakuwepekoxapop.pdfIn PDF document text
    • http://sirmamedia.com/ckfinder/userfiles/files/22720717483.pdfIn PDF document text
    • http://czyxchem.com/upload/files/4551132682.pdfIn PDF document text
    • http://anhhieu.vn/hinhanh/file/weviz.pdfIn PDF document text
    • https://togelunited4d.com/contents/files/96308767664.pdfIn PDF document text
    • http://szybkieprawko.pl/szybkieprawko.pl/user/admin/fck/file/babiwiw.pdfIn PDF document text
    • http://cpgny.com/userfiles/files/27242489355.pdfIn PDF document text
    • https://styliststudios.com/imagesTE/file/19823986548.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612efd1c97f16---kiforizuwe.pdfIn PDF document text
    • http://banquat.com/userfiles/files/45819845378.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/tobaravediwolodavon.pdfIn PDF document text
    • http://hhsmelt.com/upload/files/momafejowepetowox.pdfIn PDF document text
    • https://congtydaihai.com/upload/files/sovuxep.pdfIn PDF document text
    • https://braveathlete.net/geektic/files/bubolidutojufexiwimexa.pdfIn PDF document text
    • https://legacydockandmarine.com/wp-content/plugins/super-forms/uploads/php/files/673fe45a67f023276fc75957a7297f94/7010109282.pdfIn PDF document text
    • http://phuwangnam.com/user_file/file/72228599724.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/o37kvhrcq847k62bgd9j41t8pj/semoxitopojo.pdfIn PDF document text
    • http://shamayachts.com/upload/file/42387658676.pdfIn PDF document text
    • https://rt9.rspo.org/ckfinder/userfiles/files/zodamapumelediwuvewavejiz.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_off0000c824.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC824 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e036.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE036 17416 bytes
SHA-256: cbd0976d0da41aa73411311314a9b904a7ab98b59ec7bba4553ed764b3361ced
font_02_sfnt_off00010cf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CF8 10452 bytes
SHA-256: 5d3be4a12af7a74ffa7af40a7126c7ee925511a57486ac4b22b1639fc6ace17d