Malicious PDF — malware analysis report

Static analysis result for SHA-256 e661868bef5f4c3a…

MALICIOUS

PDF

82.5 KB Created: 2021-09-06 12:16:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a1f6f3fcd6a8f316e77f1d638c0c51c7 SHA-1: 39310fb38542e6100131ad3ebfa8ca5807c52df2 SHA-256: e661868bef5f4c3a2532bc858dedc4e180cdd27b762c3ec59242539b4f4d9bb8
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting. The document body is unreadable, but the presence of numerous external links suggests an attempt to redirect users to malicious sites for further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://dcmheavyequipment.com/admin/images/file/48689781210.pdf In PDF document text
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4691a48dd8---votuvapala.pdfIn PDF document text
    • http://modern-pro.ru/files/file/wixaxebuzoxamimin.pdfIn PDF document text
    • http://jnnycc.org/userfiles/file/21890625476.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/gralr6pbdrlb0fdk50gvkluqh6/sonenaliv.pdfIn PDF document text
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086d2c8e2429---49864224458.pdfIn PDF document text
    • https://fivetc.vn/uploads/files/14188348758.pdfIn PDF document text
    • http://nwatchonline.net/userfiles/file/82073420115.pdfIn PDF document text
    • http://ildungrice.com/fileupload/fckeditor/file/telebe.pdfIn PDF document text
    • https://facades-metal.ch/ckfinder/userfiles/files/21447094547.pdfIn PDF document text
    • http://www.hydro-tg.pro/upload/file/jurefuxomaxefojape.pdfIn PDF document text
    • http://akwarella.pl/user_uploads/file/33752524830.pdfIn PDF document text
    • http://phs1961.com/clients/2/29/29da8dc1278d8f1c58a3d16208bcb4e7/File/25137576022.pdfIn PDF document text
    • http://yummyschool.com/_UploadFile/Images/file/bijapedijixeber.pdfIn PDF document text
    • https://thesaddlebank.com/wp-content/plugins/super-forms/uploads/php/files/2uaot6rupermqk74o2in7l9mm4/3662198459.pdfIn PDF document text
    • https://unifor975.ca/userfiles/file/femesuruvojutunefapelema.pdfIn PDF document text
    • https://cmf8.ir/data/file/judamuzosomemenebefawokur.pdfIn PDF document text
    • http://reclameindex.nl/images/uploads/93845641157.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/d222643c9db6257449a3623d5b9791ca/679001013.pdfIn PDF document text
    • http://flexa.cz/docs/file/doworoziruwuxa.pdfIn PDF document text
    • http://alkanboya.com/files/file///71000593514.pdfIn PDF document text
    • http://daegyung.kr/userfiles/file/20210803025905.pdfIn PDF document text
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/29cf1544968976abb32c87f04be6c366/xabubikajuvaroji.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160f2040c52f00---nujatelepipudekapig.pdfIn PDF document text
    • http://hoanhaochemical.com/uploads/files/79315178607.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=scale+model+definition+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_off0000e115.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE115 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f927.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF927 16716 bytes
SHA-256: 1610e109b167ad0ed5593e74771704cd9e850af2288c10588438d1be6efdde47
font_02_sfnt_off000123ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123FF 10588 bytes
SHA-256: 4caf83dc25117ac34c77ca51f8c0c3c30dc16e67820f7301c6dd0192ffc4c626