Malicious PDF — malware analysis report

Static analysis result for SHA-256 16dfc031174f7344…

MALICIOUS

PDF

68.8 KB Created: 2021-09-29 06:18:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6eb9cf6b8d39954f52010acdcc77dc68 SHA-1: 3d8a26831c78520a127b287c7a2eb16fb51bcf0f SHA-256: 16dfc031174f734479bf76947375ca6f41a50b18f56f5d0fcd7212896815e35c
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to compromised CMS uploads, suggesting an attempt to redirect users to potentially harmful content. The PDF structure and the presence of multiple external URIs are consistent with a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9959

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 http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146c0a76c57f---kifururazuzukufovova.pdf
    • http://hotelbasantresidency.com/uploads/6625123548.pdf
    • http://handbook.hu/upload/page/file/40018812233.pdf
    • http://carrasvilla.es/uploads/files/raguritizavez.pdf
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/1aac510b2b1714f4cacee143f07da582/kukalozopegemu.pdf
    • http://rivebistro.net/ckfinder/userfiles/files/47915104111.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/76g4bs5kmqiehd3nmk79j6h8g6/jozuwuvusikisi.pdf
    • http://asupuro.com/upload/save_image/files/pusofom.pdf
    • https://nepoo.ro/app/webroot/files/userfiles/files/8211364153.pdf
    • http://daechienglishpark.com/ckfinder/userfiles/files/jojuxineredabasavefi.pdf
    • http://onmamtour.com/FileData/ckfinder/files/20210916_B998E08A1AAFFF89.pdf
    • http://shinex-auto.com/userfiles/file/71200418056.pdf
    • http://kpotplace.com/uploads/files/32873162200.pdf
    • https://transdeliveris.lt/userfiles/file/nasejelijoroduli.pdf
    • http://recrute.fr/files/files/4727421936.pdf
    • http://protezas.lt/i/File/17124013932.pdf
    • http://xn----8sbfhu6ab4bqv.xn--p1ai/userfiles/file/jawopedoluxexa.pdf
    • http://edins.net/userData/ebizro_board/file/sasiwifomuwokupalolaw.pdf
    • https://fishuntpesca.it/file/54172206088.pdf
    • https://hebatkeren88.com/contents/files/92879960726.pdf
    • http://jinistudy.com/_UploadFile/Images/file/55315990267.pdf
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c16217443e---sevigugejusuvixafanefube.pdf
    • http://boki.hu/editor_up/13299828469.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=harry+potter+story+about+the+three+brothers
    • 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_off0000adb6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xADB6 16792 bytes
font_01_sfnt_off0000c5cd.bin
d8d7d010049a1b31d15e179e0ba9d608fdcf40581c0685696002c23a9e031e0f
pdf-font-stream PDF embedded font (sfnt) at offset 0xC5CD 10452 bytes
font_02_sfnt_off0000dd72.bin
aec5076d098a3e3489f544171d354beeef7fb100bee4e7c1838529a1fc6d0254
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD72 15224 bytes