Malicious PDF — malware analysis report

Static analysis result for SHA-256 840a6f5b1fab06af…

MALICIOUS

PDF

84.6 KB Created: 2021-07-15 16:44:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 7851d8ca9fdfba11c7fcf4ad132b9f9b SHA-1: cefd07ac6e880493dc5b5d8681047101906a5dd9 SHA-256: 840a6f5b1fab06afcbb87c7d1ee556f8e61b8753316d81b76e2d05361fe2c3c9
96 Risk Score

Malware Insights

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

This PDF document was identified as malicious by an ML classifier. It functions as a link farm, directing users to numerous external websites, many of which are hosted on compromised CMS platforms or disposable domains. The presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicate a strong likelihood of phishing or malware distribution attempts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://medvor.ru/uplcv?utm_term=classifying+triangles+by+their+angles PDF link annotation
    • http://aivieksteslaivas.lv/userfiles/file/30738800548.pdfIn PDF document text
    • http://benardoutlite.com/admin/fckeditor/fckdata/file/52370633929.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/31d73e22cfe3b02396cfc726a00459fb/15493802590.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084f25be1fa5---55074915759.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///binugimanig.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16086062dcaa30---43366268700.pdfIn PDF document text
    • http://schooldistrictservices.com/clients/f/f6/f6ab1571d2cdf5e569af7b76e288b17c/File/dojep.pdfIn PDF document text
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/qoi7b2ssnlijn8l1r3l6ab4379/besitabubepasitawuri.pdfIn PDF document text
    • http://shethof.ch/cgi-bin/dynamisch/file/83341204560.pdfIn PDF document text
    • http://elmbbq.com/uploads/files/buporasunitopuxasi.pdfIn PDF document text
    • http://malagi.pl/user-files/fck/file/66171826587.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/gaxevamuxosajani.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1607f0cf22dac2---5356849028.pdfIn PDF document text
    • https://www.hausbootgeiseltalsee.de/wp-content/plugins/super-forms/uploads/php/files/mb6iqn2ltcu6s44pn73dehm855/sujojo.pdfIn PDF document text
    • http://ypperfect.com/ckfinder/userfiles/files/34582478753.pdfIn PDF document text
    • http://izdo.org/img/userfiles/files/najala.pdfIn PDF document text
    • http://creativeindustries.ru/uploads/userfiles/file/vunadujatonimaselujetew.pdfIn PDF document text
    • http://mnwebdesign.dk/userfiles/file/21562143854.pdfIn PDF document text
    • https://spaslask.pl/wp-content/plugins/super-forms/uploads/php/files/481lp7uvd1kkhkh6h00kfupkk7/bomokojisebaboboluwu.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c194220a84---gotitovezufotorelugebegev.pdfIn PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160739aecccc25---nitenawuzufav.pdfIn PDF document text
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/g3amqckjoeio27i6ar3f640fa5/kejajotajekego.pdfIn PDF document text
    • http://nessium.fr/userfiles/file/wipodirexodizizogafag.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/b8f21a676c5158295c5692612db6407e/11536849794.pdfIn PDF document text
    • 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_off0000e3ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fc04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC04 10660 bytes
SHA-256: aa36b7bf971701a9c761e2fc6f4f354debdd1e127714b455d9d7b5578967f51d
font_02_sfnt_off00011460.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11460 18296 bytes
SHA-256: 0ae0497e13fe4dc0f23a06b49ff22f836895096aeaa25904f920629b1661c11c