Malicious PDF — malware analysis report

Static analysis result for SHA-256 13736a20b19747c3…

MALICIOUS

PDF

70.2 KB Created: 2021-09-08 08:45:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b85602154c3659cc44ef9f6a93db9d17 SHA-1: cd79f62214cc9419b0bd3aa92eb5dea897c6a992 SHA-256: 13736a20b19747c36fe90b589fdbffb34a7c6e3dd1b6ddf80ee53525f8e5113e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many pointing to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. While no scripts were explicitly extracted, the nature of the URLs and the PDF structure suggest it may exploit PDF vulnerabilities or serve as a lure for further malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 https://catamma.ru/uplcv?utm_term=pasquinelli+diagnostica+e+tecniche+di+laboratorio+pdf PDF link annotation
    • https://mintowncoffee.net/uploads/images/files/bitun.pdfIn PDF document text
    • https://espritgt.com/userfiles/file/33199449125.pdfIn PDF document text
    • http://15881588.com/ckupload/files/xugebigemoka.pdfIn PDF document text
    • http://akgikorea.com/file_upload/fck_upfile/file/28287540577.pdfIn PDF document text
    • http://aftckwt.com/uploads/file/43183339104.pdfIn PDF document text
    • http://canyonoaksmtg.com/~duckdi5/canyonoaksmtg.com/content/file/kasurotejetiroxibeg.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/69259553714.pdfIn PDF document text
    • http://innotec-industrie.be/userfiles/file/wawemisavegebeva.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1607de8a7977fc---94607040881.pdfIn PDF document text
    • https://webshopplus.nl/app/webroot/files/userfiles/files/4912825617.pdfIn PDF document text
    • http://xn--80aafkqcanfpgnhbng3b5i9a.xn--p1ai/pict/file/96380894398.pdfIn PDF document text
    • http://diclenakliyat.com/userfiles/file/nuwavekezusij.pdfIn PDF document text
    • http://wanyuantemple.tw/userfiles/file/98116897289.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa5d6e1705b---sudonuledumu.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/160afd69473de6---22409705381.pdfIn PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/3bfedb537b656059a095f8b0d7c39d5d/duxefoxugivimuxirateke.pdfIn PDF document text
    • http://unityproductions.com/upload/files/koxowuritel.pdfIn PDF document text
    • http://minhanh.com/files/wuxupi.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607015e9032e5---84032683158.pdfIn PDF document text
    • 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_off0000b215.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB215 11284 bytes
SHA-256: 7439a7df690ca2c4cc3b693dd2a7311fcd71c763e13dda05202c02b8cf402758
font_01_sfnt_off0000cbc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBC7 15572 bytes
SHA-256: c07953f6da2f91a7367dc86293dc3115d1fa002bad391c68fe5cae4702ff0558
font_02_sfnt_off0000f382.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF382 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1