Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fef95db5d5c2eef…

MALICIOUS

PDF

95.2 KB Created: 2021-07-26 02:20:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e9528f432f40a8a2ae66b916fec7a049 SHA-1: b7eab29ffac2070842fd76362f663a99270c1ddb SHA-256: 4fef95db5d5c2eef40d92ca90a089846b9454e80edbe7cf0ff42ee2fc6b49a75
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. It contains a link farm with numerous URLs pointing to compromised WordPress sites and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing text but containing embedded URLs.

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://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/160bd6154ca278---dapede.pdf
    • http://rymwid-training.com/userfiles/file/19117733677.pdf
    • http://dagmar-e.de/userfiles/file/73423600878.pdf
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16072c4b37d857---fefodepa.pdf
    • https://nenanhduong.vn/Upload/files/toziwowipiluroxero.pdf
    • http://cansuyu.org/resimler/files/20159723643.pdf
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/f454873db750c4b9bebb6276bc6b9700/16468891533.pdf
    • http://www.halpellet.hu/userfiles/files/54162759642.pdf
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e807490e49b---kakapinuzinidodimituzan.pdf
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/12f181e5fe5061536638e644fadeaa0a/89702348681.pdf
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607fce8584c21---wuxutosaxivemomelilazaki.pdf
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160854b8f7ae77---56585038960.pdf
    • http://takeacode.net/user/d41d8cd98f00b204e9800998ecf8427e/file/xorafovuxodel.pdf
    • http://anhuishangbiao.com/upload_fck/file/2021-5-14/20210514121635490131.pdf
    • https://bustotoronto.com/userfiles/file/59877637001.pdf
    • http://plastikacz.cz/soubory/files/12348170477.pdf
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160716b87b9b6f---joguvufitemenodekun.pdf
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160af20567c3a7---68171295435.pdf
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/rgudq7fn5djhbrjgud0k4jsek5/17618868784.pdf
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/160d1ec72d2ae1---palisalifopamovu.pdf
    • https://callhfelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d7e2d88805c---20831563419.pdf
    • http://photographybynami.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f7dc46175d---lusofasolujadakizekulorol.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=how+do+you+turn+off+a+heat+and+glo+fireplace
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f828.bin
42158fba906f8a41d6e0bcd9725cde7fa54b674461698f11da89a9551e7c74aa
pdf-font-stream PDF embedded font (sfnt) at offset 0xF828 11024 bytes
font_01_sfnt_off0001117f.bin
cffdfb8a93a0b8411c8b5a296a2f033217cee1d3d38bd00ca938f58684be1a8f
pdf-font-stream PDF embedded font (sfnt) at offset 0x1117F 27884 bytes
font_02_sfnt_off000155d6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x155D6 16792 bytes