Malicious PDF — malware analysis report

Static analysis result for SHA-256 feed44a34d108a9a…

MALICIOUS

PDF

87.9 KB Created: 2021-06-29 22:26:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f8690d46f5b1c5740d3e95085a1b9731 SHA-1: f5ef3eee8193acfa164da298b0e4d0da3a5ef505 SHA-256: feed44a34d108a9a4845ab4a6a82545c03face2d24b22cfe3ad7a696bc135e62
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised WordPress sites and disposable domains, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user interaction but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://infrive.ru/uplcv?utm_term=spinach+and+bacon+cob+loaf
    • https://sport-jicin.cz/dokumenty/rasaxiredat.pdf
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a08cee531e---17591188846.pdf
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160b5439534a76---fudukatijezozisasitirili.pdf
    • http://akgikorea.com/file_upload/fck_upfile/file/nixiwikiwodewovo.pdf
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/3b3630d9ca38a2b655f51a165f608cb5/43986985595.pdf
    • http://billsky.ee/files/file/90201672645.pdf
    • https://www.djluk.co.uk/wp-content/plugins/super-forms/uploads/php/files/l54g3dc8em8dfdn903gc6pm88c/rovareneditojozogi.pdf
    • https://seataclightingalaska.com/wp-content/plugins/super-forms/uploads/php/files/d4288c920cbb2551796052948319fb9b/malipixinupozimotemafilo.pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a310a868c15---40242927602.pdf
    • https://transpack-krumbach.de/_upload_bilder/_filemanager/file/zofosozurusuwaxikuru.pdf
    • http://lifemartrealestateconnect.com/wp-content/plugins/super-forms/uploads/php/files/a41k2richml3svgq9ggdejnag2/34772010727.pdf
    • http://akcjonariusz.com/UserFiles/file/207638328.pdf
    • http://mpti.ru/userfiles/file/dokojodomekekekamufa.pdf
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080a7fae9a70---logano.pdf
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16071addd91aab---titawo.pdf
    • http://normel.org/files/upload/file/mawinuburedafuminufanegi.pdf
    • http://www.anclupnapoli.it/userfiles/file/76863404954.pdf
    • http://hurtmar.pl/Upload/file/tegovugozemiwezififexopo.pdf
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/eum38uo9g5thtq0av5p0p0gbt6/kiziwatex.pdf
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f23779a47e---89278215617.pdf
    • http://exmar.it/foto_fck/file/zokafelawib.pdf
    • https://upbilbao.com/ckfinder/userfiles/files/gedawonuwapuniv.pdf
    • http://strategie-online.net/catalogue_dynamique/file/junavagadidabenulizejovo.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_off0000f3ba.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3BA 16792 bytes
font_01_sfnt_off00010bd1.bin
ccea0821dd8788cc9929c1b62faa11421403e5e296b57c14d5952f6967e5f678
pdf-font-stream PDF embedded font (sfnt) at offset 0x10BD1 10436 bytes
font_02_sfnt_off00012316.bin
90763f8e7638ae6b9fb283336a5c30770f9c0cf1d57cea51edb7ae06ac9f4b83
pdf-font-stream PDF embedded font (sfnt) at offset 0x12316 18164 bytes