Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d88bb333146d48a…

MALICIOUS

PDF

92.9 KB Created: 2021-06-30 11:01:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4e2b4c252e5c245d240315e6af34aea3 SHA-1: f31f949d9299b4f9e82a50fc8b0ba0a0f900c2c4 SHA-256: 8d88bb333146d48a5e3bc1f8696ca80dab7ccbe33d783bfdd7f0b734af37866a
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 WordPress sites utilizing the formcraft plugin for file uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or redirection to malware. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the heuristic firings clearly point to a link farm strategy.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9927

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 http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160da580feae32---vuximatasufususiga.pdf
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/160810b9fbc4fc---57803573532.pdf
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa69e3de58---ranosuzir.pdf
    • http://pnmanagementsolutions.in/uploads/33168291601.pdf
    • https://pasarantogel2.com/contents//files/dapojonotapalajifejas.pdf
    • http://kameleonhastanc.hu/files/file/4019877422.pdf
    • http://host.keraladreamhomes.com/~viswabrahmathach/admin/fckeditor/editor/filemanager/connectors/php/userfiles/file/37990641993.pdf
    • http://jeyadhurgatemple.com/userfiles/file/7868403652.pdf
    • https://lasanisports.com/files/90713532333.pdf
    • http://robalton.es/Albums/images/file///46274596393.pdf
    • https://pabrikangka.com/contents//files/88851809753.pdf
    • https://nsck-cykelmotion.dk/ckfinder/userfiles/files/67415647967.pdf
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1609843369be97---6882003691.pdf
    • http://bjhtdszdh.com/v15/Upload/file/20215181030524376.pdf
    • http://prime-standard.com/piceditor/file/88607719369.pdf
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607139cce5fb5---satoxi.pdf
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609570546807d---vobuwura.pdf
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c236264a04---xovoxugozitirezujeforaduj.pdf
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/df5lhvpb27ojibpmkjlj3cucv2/wurezebasarip.pdf
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/adbb109d90ea94f07becc7e0e713d060/konivepof.pdf
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a93800e8bbe---10411852513.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc0be178923---17430234044.pdf
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3631f121a---vizoboxesafulutin.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=how+to+open+the+phone+booth+in+untitled+goose+game
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off0000f921.bin
a8764dac987875fa846859f339e6ee68c2f17dbd3e81a2ac54d239ffb662a07f
decompressed-pdf-stream PDF FlateDecoded stream at offset 0xF921 20344 bytes
font_00_sfnt_off0000e110.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE110 16792 bytes
font_02_sfnt_off00011b0d.bin
31adcfa0b1cfa9a0202d59855b4f24f609f6367679301b578e3955fef46aafa4
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B0D 18316 bytes
font_03_sfnt_off00014a9a.bin
76d2fe7a04ffbfed2d8fe9f98676f2e4af102d1f91b5720025e73e8214660c33
pdf-font-stream PDF embedded font (sfnt) at offset 0x14A9A 11056 bytes