Malicious PDF — malware analysis report

Static analysis result for SHA-256 1bf91dc17eee7c7e…

MALICIOUS

PDF

77.3 KB Created: 2021-07-04 04:57:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9f5452c37df75a32901a1e8c996b04c0 SHA-1: 80bc5d302de48a78baf037dbd3024bca3796c3d8 SHA-256: 1bf91dc17eee7c7e3669cb1029faffaf01c6549c110bf3fa31ad1b3f9e3b9477
164 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The document contains a link farm pointing to multiple compromised CMS upload storage locations, suggesting an attempt to host and distribute malicious files. The presence of a 'download button' heuristic further supports the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c44fd02e066---modizakosan.pdf
    • http://work4shop.cz/userfiles/file/finukomotarevaropudijoz.pdf
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d5b3638a730---31739984221.pdf
    • https://iveducentar.com/uploads/assets/file/vebakelomak.pdf
    • https://mlmrockstars.com/ckfinder/userfiles/files/79442958027.pdf
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/umoofbrvt5p55jqtefvlotg7h5/dexoritibovuvadiw.pdf
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/1609cc27f079cb---4426072610.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bae5c6cf3d2---95210889581.pdf
    • https://www.eziblank.com/wp-content/plugins/super-forms/uploads/php/files/g0nb0aau6jo7rc1nvr5e6figg1/90743463170.pdf
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/aa4lej54deev4emdv1sqd9cl52/6092489862.pdf
    • https://www.lightingdynamics.com/wp-content/plugins/super-forms/uploads/php/files/4edbc4d7bbec193a0d6994ac3bf41e8e/zapavitus.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609dc1ac873f1---46762411227.pdf
    • http://dlt-nkp.com/fileupload//file/91761412045.pdf
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/18d5b4e9c2870e7c67f82802a7aff4aa/44273176560.pdf
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16099c9c44da16---fojere.pdf
    • https://ceccargiurgiu.ro/userfiles/file/xafapilobisofirobi.pdf
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/956ef28162b9faba998fb956c95b1fa6/62490540662.pdf
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/41861215b6e49c95d37e0fa0df72970b/zunufelurewuli.pdf
    • http://theheavent.com/userfiles/files/tarerogutogumuzimiv.pdf
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/002993e28d3ff8ac4bc9a89d17dd9580/jurerol.pdf
    • https://www.kcequipment.com.au/wp-content/plugins/super-forms/uploads/php/files/2bf210c38ec9041466af5da4bb9acaf9/7703620393.pdf
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085653d8ac82---visafab.pdf
    • http://boekenwinkelindex.nl/images/uploads/55326121487.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+upload+a+csv+file
    • 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_off0000ccf2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCCF2 16792 bytes
font_01_sfnt_off0000e509.bin
abff38ae229e35d35b1a0e98bb73b76d884883dd2ada07c1c6457e3cb05e5dcc
pdf-font-stream PDF embedded font (sfnt) at offset 0xE509 10652 bytes
font_02_sfnt_off0000fd91.bin
24f8a6e8cd3fda4d6f3e9054fc7e13b9c19bcf449b4ce4bb3a26ff871387e4e6
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD91 16376 bytes