Malicious PDF — malware analysis report

Static analysis result for SHA-256 f37c3158d80c2b35…

MALICIOUS

PDF

75.0 KB Created: 2021-06-30 17:27:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: b5108603104e83d88d50b8f90f044c2f SHA-1: cd7b5a167dd54f1263905a03ea05e9cbf04c7742 SHA-256: f37c3158d80c2b355672c75d3d7c51809ac58969c9a3f8525323749a0897c10d
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to numerous external URLs, some hosted on compromised WordPress sites. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM firings suggests an attempt to obscure the true destination or purpose of these links, likely for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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=off+to+a+good+start+meaning PDF link annotation
    • http://coalcreekcentenary.com/clients/5/52/52f735e63eff8706e1a2a73a20aef632/File/42619851696.pdfIn PDF document text
    • http://cmtsport.com/pliki/2741189915.pdfIn PDF document text
    • https://hssipm.com/wp-content/plugins/super-forms/uploads/php/files/395b590dbfef713e0b978177fad1b84c/mexopakufibimetoferur.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d3ca714b9e---derivevivunofus.pdfIn PDF document text
    • https://www.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f6e4f60d15---gujigop.pdfIn PDF document text
    • https://quickonboarding.com/wp-content/plugins/super-forms/uploads/php/files/02a7d8bf4b5d938301f69d71baada769/masuxoniduki.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/i75rukhnj16p91g5prus9opob2/59939662919.pdfIn PDF document text
    • https://susta.vn/userfiles/file/popalarasiwujemesuteri.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/s45iprb4gojjo6rl9gn9cti5v2/wujobazironupigu.pdfIn PDF document text
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079ad891206b---jizomezubazatadorej.pdfIn PDF document text
    • http://juniorsmagazine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608586a58e439---pibesediravefowubore.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16084f51276013---32126461334.pdfIn PDF document text
    • https://festival.bg/fckeditorfiles/file/19667575292.pdfIn PDF document text
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/f3ca75f1bf74fff8c8c1a826835fa672/zupivemo.pdfIn PDF document text
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/ea17013160d3ff5c2b4211be6f31949b/78355426221.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a28738ed2a2---74115989396.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609e2d2298e28---18681186679.pdfIn PDF document text
    • http://hillcresthigh1971.com/clients/9/9f/9fbf9047a6869172a982db6f42f05a9a/File/jomenidus.pdfIn PDF document text
    • http://schokobrunnen.com/idata/87728049684.pdfIn PDF document text
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073aadf3c3a7---zavotolegikiwigudibuwuw.pdfIn PDF document text
    • http://delawaretravelmedicine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082cb80cbd1e---61814172574.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16081051aba57b---45985529983.pdfIn PDF document text
    • http://m2m2design.com/userfiles/77257245077.pdfIn PDF document text
    • https://cambodiaangkorhomestay.com/userfiles/file/wobefe.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/48edaabc82359a373944298438c67f27/nomezobesakifaz.pdfIn PDF document text
    • https://noddy.nu/images/file/66506156135.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_off0000c558.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC558 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD6A 16128 bytes
SHA-256: 7f0453bedf05b140e732ff0d7f051e97adf14526a6c1c3ee3234a2370a81b3d1
font_02_sfnt_off0001068e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1068E 10676 bytes
SHA-256: 73e86d082e7ac68a0654793f02500b2349ace58febfa7d4357e74c2ea8f8a294