Malicious PDF — malware analysis report

Static analysis result for SHA-256 c631dc126b20a694…

MALICIOUS

PDF

72.5 KB Created: 2021-09-14 07:11:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 8caf7d4ba4c0f315980fc0cbf5c4c169 SHA-1: 2a3d961bd4291f31f3495bd17af4406f89c189dd SHA-256: c631dc126b20a69462054bdce81b778aada3adf4b21494df4493d051d8a47a78
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised or disposable domains, 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 PDF structure and embedded URLs are indicative of a malicious document, potentially leveraging embedded JavaScript for redirection or further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://medvor.ru/uplcv?utm_term=why+can+i+not+download+apps+on+my+phone PDF link annotation
    • http://sacmacbook.net/userfiles/file/wiguvum.pdfIn PDF document text
    • http://skidubravy.sk/spravca/ckfinder/userfiles/files/5583047083.pdfIn PDF document text
    • http://pjcwyy.com/upload/file/zozitalujapupava.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a07d6954c9---13384898199.pdfIn PDF document text
    • https://insolite.lu/img/userfiles/files/44998117244.pdfIn PDF document text
    • http://seasonmediagroup.com/pic/file/kunalexasefu.pdfIn PDF document text
    • https://t-groupvnxkld.com/uploads/news_file/29446879067.pdfIn PDF document text
    • https://chungcungoaigiao.vnpec.xyz/uploads/files/27174190341.pdfIn PDF document text
    • https://siphouse96.com/wp-content/plugins/super-forms/uploads/php/files/882e639643367c54b8a846f924cc29af/33137573421.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/63889952143.pdfIn PDF document text
    • http://sungder.com/upload/lurufepebomorifotubage.pdfIn PDF document text
    • http://studiopol.com/userfiles/files/36519966281.pdfIn PDF document text
    • http://hutnia.pl/userfiles/file/72122267160.pdfIn PDF document text
    • http://paradisoseminatrici.it/userfiles/files/meruwuro.pdfIn PDF document text
    • http://kolaykanal.com/userfiles/files/77095031992.pdfIn PDF document text
    • https://s-h.cc/uploads/files/202109060834341312.pdfIn PDF document text
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/6b22f31da531efbfade66ab0392bdbf4/muzabif.pdfIn PDF document text
    • http://sujitonweb.com/userfiles/files/43651783344.pdfIn PDF document text
    • http://osayit.com/images/file/retudunax.pdfIn PDF document text
    • http://cukierniabrzezinski.pl/www/artizam/fck/file/84252918474.pdfIn PDF document text
    • https://livermore.com/wysiwygfiles/file/67937515633.pdfIn PDF document text
    • http://bukvoznaika.ru/ckfinder/userfiles/files/87537926041.pdfIn PDF document text
    • https://loyallcanada.com/editor_files/file/48549358932.pdfIn PDF document text
    • http://vikohasanfiber.com/upload/files/32951540637.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_off0000b98d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB98D 16012 bytes
SHA-256: 2b815e7c2993c32935e8d383c22d1c3d4a5af7d8f9367e086f3d4b0dd95939fb
font_01_sfnt_off0000e2c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2C0 10872 bytes
SHA-256: 957f47328c6c0ca33eaaba549456561b9098facb43facd67093a54f21e3406b3
font_02_sfnt_off0000fbd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBD1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1