Malicious PDF — malware analysis report

Static analysis result for SHA-256 31cffd6a9755baeb…

MALICIOUS

PDF

81.5 KB Created: 2021-09-09 18:09:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 133dc5f3bcb2a5e57d50e1a8bab39edb SHA-1: c51b9ade6d9573dc3652a6c2ae483fd0e64d77a9 SHA-256: 31cffd6a9755baebec899b37f5eccd913349a21b6cc8c75cfbf9c607337df283
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. Heuristics indicate the document functions as a link farm, directing users to multiple external websites, some of which are hosted on compromised CMS uploads or disposable hosting. The presence of numerous unknown URLs suggests an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://pointwebhost.com/calisma2/files/uploads/suzipazijipejemojeropov.pdf In PDF document text
    • http://www.chp.pl/ckfinder/userfiles/files/wizepupibetituta.pdfIn PDF document text
    • http://www.pvvc.cz/files/jeselugipurixufuxogujamu.pdfIn PDF document text
    • https://aakritidigitals.com/userfiles/files/14275260447.pdfIn PDF document text
    • http://tokyoracing.hu/userfiles/file/5596897085.pdfIn PDF document text
    • http://s8radziejowice-paszkow.pl/userfiles/file/liwelemetuz.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/161398c5e335f0---22389788126.pdfIn PDF document text
    • http://funagamex.vn/PhuongNamGroup/userfiles/files/89722105712.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109022316456378.pdfIn PDF document text
    • https://esportenerd.com/app/webroot/ckfinder/userfiles/files/82915035399.pdfIn PDF document text
    • http://juditphotography.com/picture/userfiles/file/32305699400.pdfIn PDF document text
    • http://artpolinakuzina.ru/pict/file/fusatufokaxudujeliwosu.pdfIn PDF document text
    • http://videotour24.com/data/fckupload/file/37814735395.pdfIn PDF document text
    • https://codecs.ro/images/file/94273151292.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/2462986432.pdfIn PDF document text
    • http://dnt-mayak.ru/content/File/vugevasususezuweb.pdfIn PDF document text
    • http://sbairs.com/datas/files/52994348277.pdfIn PDF document text
    • http://flexinform.com/hirlevel/file/33258149069.pdfIn PDF document text
    • https://rajakeempat.com/contents/files/zofiwatigivubuvapesuzubol.pdfIn PDF document text
    • https://xn--p3t29jo1ed4o4xw.tw/upload/files/fejemadadagifewimijisuzi.pdfIn PDF document text
    • http://babyshelter.net/assets/upload/files/rorogarabuvuni.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/857f5b146f9efa2bd95796e0edd8ecde/93980134000.pdfIn PDF document text
    • https://textosolutionslinguistiques.com/upload/editor/file/numolilete.pdfIn PDF document text
    • http://clinicaveterinariagussago.com/userfiles/files/89087561750.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/161390ff6cb27a---luwojazaleremalam.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=treehouses+of+serenityPDF 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_off0000dae3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAE3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f2f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2F5 17980 bytes
SHA-256: 9f8e831c52143acbc2628e18cb0a1be4f514e089684369af1ea6b4574b9f276c
font_02_sfnt_off0001213b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1213B 10280 bytes
SHA-256: ad9f340231263ec7c79f4a269dc9dada688f0dba606791ae35596168ca66c61f