Malicious PDF — malware analysis report

Static analysis result for SHA-256 9e558c300f1634b3…

MALICIOUS

PDF

88.6 KB Created: 2021-09-19 15:53:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 28d8aefa130daf2244a341ed398cc576 SHA-1: d41db3484ec5a60231461862e9bc5121d027affc SHA-256: 9e558c300f1634b31b76500cdaf33947a8ed00a782f419e0a46e5b0b15b33a02
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 http://cautrucpalang.vn/webroot/img/files/89333058135.pdf In PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/7baed9caf0bca6d9494cfd188b4e24ba/joxixifivulowopetavizi.pdfIn PDF document text
    • https://www.solucionaesp.com/ckfinder/userfiles/files/61823804648.pdfIn PDF document text
    • http://aquarium-kochi.com/app/webroot/ckfinder/userfiles/files/29353204755.pdfIn PDF document text
    • http://huile-de-nigelle.info/userfiles/file/71852080571.pdfIn PDF document text
    • https://kemxoi.vn/app/webroot/files/images/pages/files/3726445888.pdfIn PDF document text
    • https://lecourbe.dk/userfiles/file/lazewef.pdfIn PDF document text
    • http://nasfthr.com/userfiles/file/falilew.pdfIn PDF document text
    • http://artetendasud.it/userfiles/files/71226269289.pdfIn PDF document text
    • http://www.musicboxpiano.com/contentfiles/zuzuje.pdfIn PDF document text
    • http://jatyn.cn/upfiles/202109/file/1631596509.pdfIn PDF document text
    • http://studiopiergentili.it/userfiles/files/xesix.pdfIn PDF document text
    • https://maximatrimony.com/ckfinder/userfiles/files/7807851978.pdfIn PDF document text
    • http://bienchidan.org/uploads/files/55121886626.pdfIn PDF document text
    • http://springgalleryng.com/Images_upload/files/329544741.pdfIn PDF document text
    • http://pileki.com/imgup/file/gideborezoxemafebumaxid.pdfIn PDF document text
    • https://dottoridegregorio.it/public/file/fokopufarove.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/85a2cda67da1e8825eb956ad9e2d2d1a/90859466124.pdfIn PDF document text
    • http://mfcwestenkwartier.nl/beta/userfiles/file/puzex.pdfIn PDF document text
    • http://ky-auto.com/uploadfile/files/96697604735.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/16135079914aaa---14450815386.pdfIn PDF document text
    • http://crimesla.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sibidadazututeposepali.pdfIn PDF document text
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f84c783ac5---ridadozinovuvusamo.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/16134dd3c43bb6---xatepisoxulipizi.pdfIn PDF document text
    • https://padservhosting.com/userfiles/file/nusofijiv.pdfIn PDF document text
    • http://simsvizag.com/contentimages/file/30013742778.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=dnd+5e+baldur%27s+gate+descent+into+avernus+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_off0000f2ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2AD 11272 bytes
SHA-256: 3ed9842e7253d6ad5d47ac9727b91604eaf5ee7f5595c83c5842fde132bac3ef
font_01_sfnt_off00010cfa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CFA 18136 bytes
SHA-256: 901c1d5ef766b085295549d8c48b454aa27ba2d486d0a0df4ba853841577eac4
font_02_sfnt_off00013bb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BB0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1