Malicious PDF — malware analysis report

Static analysis result for SHA-256 638170edffb645b4…

MALICIOUS

PDF

71.5 KB Created: 2021-09-26 06:32:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 20dd9918c65d99891303e61448524e0f SHA-1: c02dba52bef6da9ff49c1ffbd3d49c5a85d0165f SHA-256: 638170edffb645b4824b993294e6dfb423588e5f42ddfaa77fbc9074c0488e2d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of numerous embedded URIs, many of which are part of a link farm on disposable hosting, strongly suggests a phishing or malware distribution campaign. The document body is heavily obfuscated, but the overall structure and heuristic firings point towards a malicious PDF designed to redirect users to external, potentially harmful, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://oniceh.ru/uplcv?utm_term=comando+para+calibrar+bateria+android PDF link annotation
    • http://asbu.net/uploads/FCK_files/file/pamopimanezok.pdfIn PDF document text
    • http://orgue-chantepie.info/FCKeditor/upload/file/28248072713.pdfIn PDF document text
    • http://umhouses.com/uploads/files/4787508063.pdfIn PDF document text
    • http://www.ppk-kp3k.kkp.go.id/ver2/extra/ckfinder/core/connector/php/media/ckfinder/files/81916259977.pdfIn PDF document text
    • https://codecs.ro/images/file/muwadisemapajezo.pdfIn PDF document text
    • http://ferramentabelleggia.it/public/file/6415679666.pdfIn PDF document text
    • http://ominocoibaffi.it/userfiles/files/31395059966.pdfIn PDF document text
    • https://landviewdesign.com/userfiles/file/xevazetazov.pdfIn PDF document text
    • http://52fotki.ru/ckfinder/userfiles/files/nodijiwi.pdfIn PDF document text
    • http://thechitay.com/uploads/userfiles/file/84053330327.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file///35681741574.pdfIn PDF document text
    • https://viettincapital.vn/upload/files/jixepafazapov.pdfIn PDF document text
    • http://stelmart.ru/userfiles/file/rowenerovav.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/8002fa946ef6ee6853d218ae9b5e5f25/53000249778.pdfIn PDF document text
    • https://medtek.vn/storage/file/74094449124.pdfIn PDF document text
    • http://clevio.biz/fckUpload/file/zonofomaborigu.pdfIn PDF document text
    • http://studiolorenzino.eu/userfiles/files/34199550729.pdfIn PDF document text
    • http://zenkatsu.dk/files/fovilafobamoderup.pdfIn PDF document text
    • https://clubesolbra.com/uploads/files/81014295051.pdfIn PDF document text
    • https://textosl.com/upload/editor/file/buwogotinujogaroxi.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/dalexokixadaxamumagumam.pdfIn PDF document text
    • https://jodhpurtravels.com/nbloom/fckuploads/file/kubapozowezer.pdfIn PDF document text
    • https://promenade-perpignan.com/userfiles/file/vofapepebanojaxofe.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/e7fee1853fce821061b645255274cee1/zuvojujaxevobir.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_off0000b347.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB347 10680 bytes
SHA-256: 5f3dab29001490a8bf9243be98fbe7ebd3df7f8420bff129e64b9a3b86f4d45c
font_01_sfnt_off0000cb76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB76 17388 bytes
SHA-256: 3729ac7b37c2f4b934cbf85f186d38aeee407ccb5df61d6429bc505c3ade99e8
font_02_sfnt_off0000f8a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1