Malicious PDF — malware analysis report

Static analysis result for SHA-256 35fb7886e249c0b2…

MALICIOUS

PDF

93.0 KB Created: 2021-07-08 08:35:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bbcc218b2927c20739ef42cf79163c04 SHA-1: d34bd11cbbd7fd5c07ef2e6aefc8da4967dbc1d9 SHA-256: 35fb7886e249c0b2bacb0a65c7a6a4781b2edb940cf60eaed6f0fa4edf30b0af
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many pointing to compromised websites or disposable hosting, indicative of a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics reveal.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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://maspacientes.es/wp-content/plugins/super-forms/uploads/php/files/m2jadf0ji8bct8urjsvkd4varr/23600756094.pdf
    • http://vksraja.in/fckeditor/upload/file/masetijetegubamesax.pdf
    • http://phuwangnam.com/user_file/file/xizexidifu.pdf
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf82e9200cb---79046580209.pdf
    • https://bouveau-consulting.com/userfiles/file/37670500248.pdf
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160942f8334bde---mozidexunusabonuf.pdf
    • https://mfdesign.hu/files/file/jutudopodiginuziwowanufa.pdf
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160a3622a19850---12713874376.pdf
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/1155f152ad9c1fd875ecb1c0e97e49d5/17625885478.pdf
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/vtjksdhcm49abfjqsd6od0l1u3/mebobafonokinomeledirivi.pdf
    • http://ferrocom-spb.ru/userfiles/files/barumowizuzox.pdf
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607b997146d8c---84403999470.pdf
    • http://benardoutlite.com/admin/fckeditor/fckdata/file/93766309501.pdf
    • http://hotelstrack.com/bot/ckfinder/uf/files/6488526503.pdf
    • https://qualitymattressfactory.com/admin/userfiles/file/97026774777.pdf
    • http://iwilldoit.ru/uploads/files/files/66489886699.pdf
    • http://mnogonomerov.ru/uploads/file/nilubedisinusa.pdf
    • https://useoneconvo.com/wp-content/plugins/super-forms/uploads/php/files/ec04503fa6b0da42235e10ca5c450410/11393112553.pdf
    • https://bearings.vn/images/ckeditor/files/49165949508.pdf
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/5shaoogi17g2s9it5dt9birlc4/86521121532.pdf
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160a74288b522c---gegemor.pdf
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/vmui25uueqean493lu5dd462v5/8193780302.pdf
    • http://www.firengo.com/userfiles/files/konaruwetikojujojo.pdf
    • https://perfecthospitals.org/FCKeditor/file/rufitelupi.pdf
    • http://konemara.hu/userfiles/file/bezuwup.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=japanese+encephalitis+vaccine+cost+in+india+2020
    • 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_off000103ee.bin
a6068a271f34dc432973a8e543849f43d7acce7840138ca9e1a5e05f8a4b5d7a
pdf-font-stream PDF embedded font (sfnt) at offset 0x103EE 10812 bytes
font_01_sfnt_off00011cd9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11CD9 16792 bytes
font_02_sfnt_off000134eb.bin
130a7edfb331ce6a339d12c8c4daaf0d1c64f8ff958b2a0eca227271adb790bb
pdf-font-stream PDF embedded font (sfnt) at offset 0x134EB 18672 bytes