Malicious PDF — malware analysis report

Static analysis result for SHA-256 6843d17b7b58f5cb…

MALICIOUS

PDF

88.5 KB Created: 2021-07-18 16:05:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4aea40475184622a384eda5f5638a2e6 SHA-1: 5f4f1ee65b59e60d619184171568ca747fd10237 SHA-256: 6843d17b7b58f5cb67ecea3925fdc4edc2bfcf5daf73c5ed75aabe025f92daba
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a link farm pointing to multiple URLs, many of which are hosted on compromised WordPress sites. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/6775f901fbea776110b7a429bd0a2d2c/55764187486.pdf In PDF document text
    • http://toanthinh.vn/webroot/img/files/xekividibufafaxixod.pdfIn PDF document text
    • https://suksesunited.com/contents//files/61007456144.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c02e9928584---19975804696.pdfIn PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/9f7346f5c70c42173d38a0f6c41538f0/41970472204.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad6c9930e6c---minutiwipukonot.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/366096e419e1f2c6bd4d24a5c0ce914c/jedonorunokolavofez.pdfIn PDF document text
    • http://reversetheclocknow.com/ckfinder/userfiles/files/tixesapiwub.pdfIn PDF document text
    • http://ehhs1969.com/clients/6/67/67a0fa02f482ea8575b7cec7429e43a8/File/82852332024.pdfIn PDF document text
    • http://laser-piskovani.cz/democms/userfiles/file/wimerurujesozudolo.pdfIn PDF document text
    • http://yuha.be/_files/file/fivudoku.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608623c01ad70---dosogixobikujuvosur.pdfIn PDF document text
    • https://cal.lighting/wp-content/plugins/super-forms/uploads/php/files/56d1b90ac24e13bd5cc49c0a2ef396f8/reteperuvenexa.pdfIn PDF document text
    • http://gustosandvic.com/ckfinder/userfiles/files/48654066345.pdfIn PDF document text
    • https://eminencesolutions.in/resources/userfiles/file/sivirazelazob.pdfIn PDF document text
    • http://redwoodpwr.com/wp-content/plugins/super-forms/uploads/php/files/qbda2bb2r7jiklgicg97ttajs0/jivepo.pdfIn PDF document text
    • https://orldoc.ch/wp-content/plugins/super-forms/uploads/php/files/o8lq0ds7lshuda800sqpil1hk1/sedonok.pdfIn PDF document text
    • http://rockoncharters.net/home/rock/public_html/ckfinder/userfiles/files/kofesujatopalaveri.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b561bba267c---zozalesubujux.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/160847b1599248---63538726733.pdfIn PDF document text
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/76516611ff55d679741afdeb04948c22/pevemafonabugor.pdfIn PDF document text
    • https://victorybear-info.com/userfiles/files/gopun.pdfIn PDF document text
    • http://moristas.com/userfiles/files/wekibuzokejawupup.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/868110372.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/2osvffeb3guq56btjjuj174fdq/21602427112.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=m+letter+words+for+kidsPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f80f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF80F 10252 bytes
SHA-256: 676591fc51613cb198b648bf63183c8aa9d5a12e49f38c09012c94747ebf5650
font_01_sfnt_off00010f49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F49 17340 bytes
SHA-256: 9a00e82f3f6f7100a61b9aa93aa9b420214c66589bb86030ace1d9cffdf279fe
font_02_sfnt_off00013c94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C94 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1