Malicious PDF — malware analysis report

Static analysis result for SHA-256 f851aa43b980e3b7…

MALICIOUS

PDF

90.1 KB Created: 2021-09-01 04:54:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 341e6a3c5e13db324a1cafeb6d5f8208 SHA-1: 88a101e2891d2b37d921dfe17f058d0d5a0fc74e SHA-256: f851aa43b980e3b78ad67060d7293fbe1d379f6883a2d39b3e12ba05de0d6587
104 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external URIs suggests it's designed to redirect users to potentially harmful content. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the link farm heuristic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 6

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://queure.ru/uplcv?utm_term=perimeter+and+area+class+7+online+test
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/c8sqvji4cphnunai60q28psrtm/65604309538.pdf
    • https://area5srl.it/file/38986260865.pdf
    • https://exporoaster.com/app/webroot/files/images/pages/files/64865880957.pdf
    • http://clarkstownhs64.com/clients/2/25/255c49a504cbad61718694d8b78dfcdd/File/jalumisolip.pdf
    • https://www.escon.it/wp-content/plugins/super-forms/uploads/php/files/4a3cdd914699b3731f71641d6ca1902e/59266839727.pdf
    • https://sapsda.org/SapmaUserfiles/file/xelikemeriva.pdf
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/c4d0d80a946b5c352570974d4ecd18f0/nifepe.pdf
    • https://qfse.co/images/uploaded_files/ckfinder/files/1630456492_b87fcffb17.pdf
    • http://peoplefineart.com/assets/202109/files/20210901060824799055.pdf
    • http://soles2walk.cz/data/file/60161784268.pdf
    • https://roofmed.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161246ca33d49f---kifasimudowuv.pdf
    • https://www.nosolodespedidas.es/wp-content/plugins/formcraft/file-upload/server/content/files/16086a5d46514c---labukuzas.pdf
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd178916e45---25000823035.pdf
    • http://hertzlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/39739454416.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d410cc19a79---74651014463.pdf
    • http://nashcentralfalcon.com/clients/d/d5/d5bea9c86035def548a020f7371d19fe/File/wubemekububotinonapufil.pdf
    • https://mimpishiodua.com/contents//files/numevusadulawepixalavob.pdf
    • https://alienaquatics.com/home/gb/public_html/ckfinder/userfiles/files/tinuli.pdf
    • http://skupka54.ru/upload/m/12373250966.pdf
    • https://vico-immobilien.com/ckfinder/userfiles/files/redilonijutedexezoxonora.pdf
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d72fd0cc281---nogegodon.pdf
    • https://anfauglir.com/images/file/xawulela.pdf
    • https://www.alignerco.ca/wp-content/plugins/super-forms/uploads/php/files/3e6971ba642d6f4a17a44ce3621a0a28/jimud.pdf
    • https://vvpta-irvine.org/userfiles/file/pepuwewimemix.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_006_off0000f967.bin
ade20bdaee39fc0809bf6ced49dc79745c54736d9aa4143467242252c5bfda62		 decompressed-pdf-stream PDF FlateDecoded stream at offset 0xF967 17568 bytes
font_00_sfnt_off0000e156.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1		 pdf-font-stream PDF embedded font (sfnt) at offset 0xE156 16792 bytes
font_02_sfnt_off00011414.bin
fca7a14ef95bbf0a3ad25dc287cbb842cb8bd818ac60608e380732002d92beab		 pdf-font-stream PDF embedded font (sfnt) at offset 0x11414 10584 bytes
font_03_sfnt_off00012c3f.bin
a0d444481830427ad84e99c34366975d6c70810a8126be83c3f25d677b8a70e9		 pdf-font-stream PDF embedded font (sfnt) at offset 0x12C3F 17256 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.