Malicious PDF — malware analysis report

Static analysis result for SHA-256 3954f282fdce5d42…

MALICIOUS

PDF

70.3 KB Created: 2021-10-03 18:57:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 7e12e99b056b474a20083f24f61d374a SHA-1: 3f5a4abb3777e2d05946632d845130873c3e64da SHA-256: 3954f282fdce5d4230bcf09ee4678cdaa02afd858558942c7ec8cb7859615a4b
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating it is likely a phishing or malware distribution lure. Multiple heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. The embedded URLs and the nature of the heuristics strongly suggest an attack pattern involving spearphishing attachments leading to external malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://grupo-kayros.com/userfiles/file/89984398838.pdf In PDF document text
    • http://slxiang.com/v15/Upload/file/202199227505131.pdfIn PDF document text
    • https://ketex.com/trcgp/ckfinder/userfiles/files/48643291335.pdfIn PDF document text
    • http://artdealer.vn/upload/fckimagesfile/2ce217c297e28ee1d189bc0330bc8f4e.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/29ee1b5dc9380f550c4a498b931af9f9/vuxerukonisu.pdfIn PDF document text
    • http://dtjxbpzx.com/filespath/files/20210913060942.pdfIn PDF document text
    • https://alice-immo.com/userfiles/file/bojopirun.pdfIn PDF document text
    • https://equipelec.fr/ckfinder/userfiles/files/36369412208.pdfIn PDF document text
    • https://kungfuclasshongkong.com/louis/taichi/ckfinder/userfiles/files/pilavimabir.pdfIn PDF document text
    • http://brixtontaxi.com/survey/userfiles/files/65439799775.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613ddef09d66d---divumodetixelaxudul.pdfIn PDF document text
    • https://esperidiaogomes.com/userfiles/files/vaviguxavupaliradi.pdfIn PDF document text
    • http://uniroll.pl/user_images/file/67180235670.pdfIn PDF document text
    • http://reicar.dk/userfiles/file/7939100832.pdfIn PDF document text
    • http://bjjiffy.com/upload/nurabixisawubux.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1614e3ccd60521---12900286413.pdfIn PDF document text
    • http://sntaviator.ru/ckfinder/userfiles/files/duvof.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files/gijirusujepawimawa.pdfIn PDF document text
    • https://willes-gb.com/uploads/files/202109031137057773.pdfIn PDF document text
    • http://www.sintsprev-ms.org.br/ckfinder/userfiles/files/83404797318.pdfIn PDF document text
    • http://group-anons.ru/userfiles/files/jukezugepije.pdfIn PDF document text
    • https://demoepaper.104portal.com/upload/serback/files/20210925220409.pdfIn PDF document text
    • https://popa.com.br/wp-content/plugins/super-forms/uploads/php/files/a0479b38863723b1b03d7f232f1cc081/61936752239.pdfIn PDF document text
    • http://flexinform.com/hirlevel/file/tebav.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=6+feet+in+cm+and+inchesPDF 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_off0000b21a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB21A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA31 10548 bytes
SHA-256: 948fd090d5314474c5efc4e0028101fe2599292ed309f14b464ec1118bfd0668
font_02_sfnt_off0000e1ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FF 16240 bytes
SHA-256: dd37b904cdf2186f21db03c4a2ed99c01363cf138be4d1979311901e2e671a95