Malicious PDF — malware analysis report

Static analysis result for SHA-256 845c8779b12e4f68…

MALICIOUS

PDF

88.7 KB Created: 2021-07-05 20:14:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7b99ac008c06957a592e331fb2bb25bc SHA-1: cb5cf508ad5ae15f50f22ea15ede486f57967691 SHA-256: 845c8779b12e4f68b508344b324e0b79f0bb9cb40467375d03c547c0ae425875
96 Risk Score

Malware Insights

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

The ML classifier strongly indicated maliciousness, and the heuristics reveal the PDF functions as a link farm. It contains numerous external URIs, many pointing to compromised WordPress sites, suggesting an attempt to leverage these for SEO or to distribute malicious payloads. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 5

  • 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://dynasty888.com/image/files/20210529_033346.pdf
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607177535c322---kadilinobazurogux.pdf
    • http://quickvideo.nl/userfiles/file/tipodebinade.pdf
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/614af20e86638e6647cde402827a6a4f/rupaxuvosim.pdf
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/160813068667f8---12844463587.pdf
    • https://vildmarksjagt.dk/userfiles/file/32194740116.pdf
    • http://ettorebelfioreliutaio.it/userfiles/files/gagibarodovijaravevukim.pdf
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1609877a946c8b---piwifiwirixuludekepuvow.pdf
    • https://bodegoncriollo.com/userfiles/file/lopipi.pdf
    • http://1975geegees.com/clients/78603/File/53154096210.pdf
    • http://salinahighschool1968.com/clients/3/33/33fcb9b832a528c934b1ac42c6b88a99/File/34388693712.pdf
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/0d59e8b8a8b10992264a6c1c4fde0eaf/riradixubove.pdf
    • http://asiavent.com/UserFiles/file///kipitasegawenefofijadexa.pdf
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/2edc85879b0a7baa87345cdda34dd7b3/riferemifanuxitawugesexe.pdf
    • http://nhs1980alumni.com/clients/878257/File/21431299759.pdf
    • https://planet-for-events.de/userfiles/file/36363481629.pdf
    • https://www.marbelitesa.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607ff50c72fcc---34761766717.pdf
    • https://artasedanasingaraja.com/uploadfck/file/tozifawexo.pdf
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/8bbbe0bc2cc5a02b4fff6a53ab9cee48/mebujejibebuvefume.pdf
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9830b8bb57---gapulik.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=constant+burping+after+food
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fd71a4dcbf---runurizopevo.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_off0000f797.bin
64ed6d6868144ba27bde3b6e1c491db29f5a1e899e7b086d309f3468508ac6fd
pdf-font-stream PDF embedded font (sfnt) at offset 0xF797 16716 bytes
font_01_sfnt_off0001233a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1233A 16792 bytes
font_02_sfnt_off00013b51.bin
a20e56c4644ddf04a2ed6e181da25d0569f7a713a09dd4ea58e9b2bf9c4e3566
pdf-font-stream PDF embedded font (sfnt) at offset 0x13B51 10896 bytes