Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c8562a1403f1341…

MALICIOUS

PDF

87.3 KB Created: 2021-09-02 18:09:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 8b1883a4a6ebb1b893079292f8983258 SHA-1: 40e69eef7722efea99933d67fcc075947444ef29 SHA-256: 9c8562a1403f1341d717b1dddb2e894fa811819673c25d0354f037e470217d48
156 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to various websites, many of which appear to be compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. The presence of multiple external URIs and link farms suggests an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 6

  • 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.
  • 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://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608054c395a8e---5996568811.pdf In PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/160e4c84b76bb2---bilivopu.pdfIn PDF document text
    • http://dlabiura.kbo.pl/ckfinder/userfiles/files/5715202982.pdfIn PDF document text
    • http://hylimusic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/4589675592.pdfIn PDF document text
    • https://deedpoll.sg/wp-content/plugins/super-forms/uploads/php/files/05736f84b826ae92eb093047c00a259c/wajulenu.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5d9c81ac05---fomikusuw.pdfIn PDF document text
    • https://www.properties-thassos.com/wp-content/plugins/super-forms/uploads/php/files/73591u7p5haokcnaqvja74q7ag/80502649040.pdfIn PDF document text
    • http://volkshilfe-ktn.at/images/content/files/bopujakevadurugejiv.pdfIn PDF document text
    • http://ozanatalan.com/iboard/includes/userfiles/files/bumimarusuwiguvajuj.pdfIn PDF document text
    • http://kimhoatra.vn/upload/fckimagesfile/12439215823.pdfIn PDF document text
    • http://abwmercury.com/uploads/files/4248527635.pdfIn PDF document text
    • https://panificioilcavaliere.it/userfiles/files/riwuzexunojupat.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/ad9466b3ca3ed9267c4779549eaf2572/17545844947.pdfIn PDF document text
    • http://odesignlab.ru/admin/ckfinder/userfiles/files/95327663215.pdfIn PDF document text
    • https://kabelkyaobuv.sk/editor_uploads/files/tusarepijubenaxute.pdfIn PDF document text
    • https://shiokuda2.com/contents/files/3252558721.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/161295f6a23a85---22388727602.pdfIn PDF document text
    • https://ctapigroup3.com/contents//files/49328210783.pdfIn PDF document text
    • http://lnyuanzong.com/uploads/files/20210629002132.pdfIn PDF document text
    • https://dannysacademy.com/ckfinder/userfiles/files/dokasegederigedipidi.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/160798d49d69a9---tubibetewuragorutumawuvi.pdfIn PDF document text
    • http://choinka4x4.org/cms/files/file/remododafefoduwavozaxik.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=scriptures+on+deliverance+from+strongholds+pdfPDF 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_off0000ee16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE16 18408 bytes
SHA-256: 03bd142eaefce5cd62b3d7debdb93bf1f706fe3fccdb4e07d6d78eb7cb53abbe
font_01_sfnt_off00011d5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D5B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013572.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13572 11308 bytes
SHA-256: 6ac05655a92cfd4a2f47f5420a68cfe262dc0b6c6682a309a0fd4157d2b6e257