Malicious PDF — malware analysis report

Static analysis result for SHA-256 85afa6af5097bcfa…

MALICIOUS

PDF

76.3 KB Created: 2021-09-10 09:11:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 0a190188b2183206ef6ef0305162b0ad SHA-1: 0b5c3615ae8dfbe88965525ae006d62796d41f50 SHA-256: 85afa6af5097bcfa69c904a8d3af737d4d88b7ba50796baba6e9335c9148355d
126 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, many of which point to PDF files on distinct domains, indicating a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this is a tactic for SEO poisoning or distributing further malicious content. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://yomamasushitogo.com/uploads/files/podegawiwisimawutil.pdf In PDF document text
    • http://rc-saty.cz/gais/image/file/35335986012.pdfIn PDF document text
    • http://mylodge-naoshima.com/dutidijoxotodefofuzofi.pdfIn PDF document text
    • http://entryexpress.online/chapter_images/files/kenerulexemoj.pdfIn PDF document text
    • http://kirsanov-maslo.ru/uploads/xowepofekukuzotozamefifat.pdfIn PDF document text
    • https://ckfinder.pamlskovnik.cz/ckfinder/userfiles/files/49961516168.pdfIn PDF document text
    • http://opt-russtd.ru/data_center/upload_pictures/file/85249965237.pdfIn PDF document text
    • https://recapress.com/ckfinder/userfiles/files/50684631195.pdfIn PDF document text
    • https://bunyaminerdemir.com/resimler/files/27541162592.pdfIn PDF document text
    • http://daearesort.com/FileData/ckfinder/files/20210909_D862BC6593B777D4.pdfIn PDF document text
    • http://vnndt.com/Images_upload/files/nudovepuw.pdfIn PDF document text
    • http://gandolfiarchitetti.com/userfiles/files/280662240.pdfIn PDF document text
    • http://sjanzee.nl/file/21742931479.pdfIn PDF document text
    • http://telegid.tv/userfiles/files/61062748354.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/161368472c5a14---37771815815.pdfIn PDF document text
    • http://alacarte-design.de/userfiles/file/vonujixawenaji.pdfIn PDF document text
    • https://aymfly.com/aym_image/files/likixiwuju.pdfIn PDF document text
    • http://0851gay.org/userfiles/202109file/2021090610573070554.pdfIn PDF document text
    • https://www.frontieregypt.com/sites/all/libraries/ckfinder/userfiles/files/81846545187.pdfIn PDF document text
    • http://rothemtour.com/FileData/ckfinder/files/20210908_7ED5EA0C8D45A6BF.pdfIn PDF document text
    • https://egc.ecrom.work/syo/files/zapizunagavuruf.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/n1vs305d2olmi7umjtpp2gha35/fusoziluwu.pdfIn PDF document text
    • http://toptoptraining.ru/img/upload/file/denafuraxomusi.pdfIn PDF document text
    • http://dream-mebel.com/pic/file/rusesezugefaxajirivijinov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=one+piece+stampede+dub+kissanimePDF 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_off0000c745.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC745 16836 bytes
SHA-256: fb5176a82e4480345b4ed2336f310b4f3b3ffb20262d893e50ce2e1575f7aa9d
font_01_sfnt_off0000f2c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2C7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ade.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ADE 10768 bytes
SHA-256: e6cb181365b63bf7b8aa2b8c01770c89e94b511cb49998459b16775616985dd4