Malicious PDF — malware analysis report

Static analysis result for SHA-256 5733f2fc7b2c70bc…

MALICIOUS

PDF

75.2 KB Created: 2021-09-16 14:57:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4db9c388c88451f44042bc3d46c98691 SHA-1: 9a9042c6a8f9724cd1663510a2deae1c1f63a828 SHA-256: 5733f2fc7b2c70bc489390b39cc955f4c36429a2dca8d01dc3a453f28fdf6cb7
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. It contains numerous embedded URLs, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of 'utm_term' in one URL further indicates a phishing or spamming campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://pistant.ru/uplcv?utm_term=mortal+kombat+x+mod+download
    • http://nbmounts.com/userfiles/file/1631528933.pdf
    • http://montaze.org/democms/userfiles/file/31316762134.pdf
    • https://stpatswatertown.org/ckfinder/userfiles/files/28311504577.pdf
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f2b209ace5---xijugagosem.pdf
    • http://modnyi-buket.ru/uploads/files/32424957939.pdf
    • https://avflash.nl/upload/files/rubir.pdf
    • http://cathugo-catamarans.de/res/wysiwyg/file/gerewuso.pdf
    • http://letsfinal.com/userfiles/file/53191209364.pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/rk5uabbucm32bvghhg6hh2e5is/24326514907.pdf
    • https://hgb.se/filer/file/5992400823.pdf
    • http://xn--80aafkatcapceshpicpg3h.xn--p1ai/pict/file/buzojotenowewujaf.pdf
    • http://satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/gumabasivebaw.pdf
    • http://kuehllawpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/5690479464.pdf
    • http://sendedianqi.com/upload_fck/file/2021-9-16/20210916022155707053.pdf
    • http://katour.ru/admin/ckfinder/userfiles/files/jevoliwatinuzobegi.pdf
    • https://bindazzled.com.au/wp-content/plugins/super-forms/uploads/php/files/9b9ac3cec62e7db16164af594237e6ac/23580635736.pdf
    • http://hotelbasantresidency.com/uploads/84464958580.pdf
    • http://smm-mm.com/uploads/news_file/dikapiruxubofowupige.pdf
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16141e6177b00b---55171047749.pdf
    • https://ta-taiwan.com/app/webroot/userfiles/files/poparasimesajop.pdf
    • http://huile-de-nigelle.info/userfiles/file/35488479970.pdf
    • http://giustizianuova.it/userfiles/file/25540517206.pdf
    • http://astorandblack.net/emailer/userfiles/file/ganafigof.pdf
    • 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_off0000c4f7.bin
a033456682fe335a4fc7e3abfc6e6770fd44d5f7f91012be1e182b1d166b852b
pdf-font-stream PDF embedded font (sfnt) at offset 0xC4F7 10428 bytes
font_01_sfnt_off0000dca4.bin
bf9a9df59a4d3814c3a6943dd0a4803b26c15b02830e55c7c29eb2570d054ca0
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCA4 16656 bytes
font_02_sfnt_off00010793.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10793 16792 bytes