Malicious PDF — malware analysis report

Static analysis result for SHA-256 553aca53af01d613…

MALICIOUS

PDF

72.9 KB Created: 2021-09-18 19:55:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 65f1ea928473b6793f14a62da6b61be6 SHA-1: 014387ba2767ba0a1a899edac94c0f94c9f277cf SHA-256: 553aca53af01d6133c5bdfacb43210f3bfdb157129752870d466e50f6a9d7b52
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://homestayhoian.vn/uploads/image/files/beguwovulup.pdf
    • https://autohausnschmidt.de/userfiles/file/45103323103.pdf
    • http://erisalaw-chicago.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/13864293292.pdf
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ebc00c93f0---momewipuga.pdf
    • http://www.azurwelcomeservices.com/userfiles/file/11716689992.pdf
    • https://geniodelweb.com/file/domijaguzi.pdf
    • https://associazionedynamica.it/uploads/file/jiginarojolux.pdf
    • http://ancheng-medical.com/uploadfile/files/nifujipowubu.pdf
    • https://www.ruchya.com.tw/upload/files/duvab.pdf
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/eb0e6eae47cc009f775b1978926e8070/begofojopek.pdf
    • https://vinocastillo.hu/editor_up/gogatikofowikerikowivo.pdf
    • http://amdind.com/userfiles/file/76294081359.pdf
    • http://www.trackls.com/application/ckeditor/ckfinder/userfiles/files/89013533406.pdf
    • http://chongthamnguoc.vn/img/files/kifusozokudil.pdf
    • http://dmhu.eu/uploads/uplib/file/nazurowesunel.pdf
    • https://dichvumayphoto.vn/webroot/img/files/vavadokigotixujet.pdf
    • https://hobbes-group.com/upload/files/zokadaketaturidugudoku.pdf
    • https://mfdesign.hu/files/file/tajegegef.pdf
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/f55edcd6b00cb6cff0c0357b6739b428/disirabitum.pdf
    • http://kompassztuki.pl/Image/files/ludajutix.pdf
    • http://launensia.cz/ckfinder/userfiles/files/61518342025.pdf
    • http://france-ex.com/images/blog/file/kiluxebaxokomi.pdf
    • https://umutfm.com/resimler/files/sodexemepogomisujumumof.pdf
    • https://opsclown.it/ckfinder/userfiles/files/15107657303.pdf
    • https://sikanderajam.com/Robinson/ckfinder/userfiles/files/15814550743.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=android+edittext+numberdecimal
    • 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_off0000b8c2.bin
1fa5c0ca7610f417013e9d824bc45f0000f213927c1d56db83a4dd8db6c7f585
pdf-font-stream PDF embedded font (sfnt) at offset 0xB8C2 17424 bytes
font_01_sfnt_off0000e5b9.bin
53234641950db5ff241a0e1f82616cc0b998466a78d5bc1b410ad112c26b4d54
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5B9 10684 bytes
font_02_sfnt_off0000fe38.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE38 16792 bytes