Malicious PDF — malware analysis report

Static analysis result for SHA-256 23ebbda341b24893…

MALICIOUS

PDF

85.0 KB Created: 2021-09-05 06:47:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 64dc0764476486e99bd13d1c279897af SHA-1: 1563179a07ab01b71fb567d32dff1d9cab570df5 SHA-256: 23ebbda341b24893dc9fca04f5a71530c583ea55be7583386db3d4eea2655469
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan threat. It contains numerous links to compromised WordPress upload storage and disposable hosting, suggesting it's part of a link farm designed to redirect users to malicious content. The document body is heavily obfuscated, but the presence of external URIs and link farm heuristics points to a social engineering attack aiming to trick users into downloading further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://rtm-plus.com/ckfinder/userfiles/files/15557401013.pdf In PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160999f980e72b---mirukawofuj.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ac2b442fa3---1418298861.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/16074b4e8535f1---4338815486.pdfIn PDF document text
    • http://alpha-cp.com/userfiles/file/24521350788.pdfIn PDF document text
    • http://finvestfortune.com/admin/userfiles/files/4990428397.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611fcf5c748e0---47081948032.pdfIn PDF document text
    • https://aashianarealty.com/file/saropujejabil.pdfIn PDF document text
    • http://pokorny-podlahy.cz/UserFiles/File/88438098857.pdfIn PDF document text
    • http://uitetenindex.nl/images/uploads/49101661249.pdfIn PDF document text
    • http://www.nomorcantikjoss.com/file/leguse.pdfIn PDF document text
    • https://www.edmcenter.xyz/ckfinder/userfiles/files/64418820167.pdfIn PDF document text
    • http://work4shop.cz/userfiles/file/84741061266.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/160872684da613---46248145774.pdfIn PDF document text
    • http://hanasushichoice.com/uploads/files/zipoduteliniwo.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/ebe70fe64b83ee1835acf73b1c883fb7/60644722276.pdfIn PDF document text
    • http://e-pisanie-prac.pl/famprojekt_z_serwera/images/file/25794121802.pdfIn PDF document text
    • http://indianspringhomes.com/userfiles/files/20117264585.pdfIn PDF document text
    • http://hotel-ambassador-nice.com/upload/files/56776935597.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/160885ef3b415d---woxonefigemagu.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/oxugiwanakonupeb.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/160bd48484e20a---99473969399.pdfIn PDF document text
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d78085ed0f---nudebizuxotisifus.pdfIn PDF document text
    • https://puppometalli.eu/file/7002736872.pdfIn PDF document text
    • https://muacash.com/webroot/img/files/porejebamubewifog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=piaggio+liberty+125+service+manual+pdfPDF 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_off0000dfb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFB6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f7c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7C8 19496 bytes
SHA-256: 570e24a120654d726db276cb382279d99584e262bcef392dda169388e8ebb7f6
font_02_sfnt_off00012ac9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AC9 11688 bytes
SHA-256: 83c6060f82c6bb589df894198e7f0966641901c19fd1daa278a625e01c475698