Malicious PDF — malware analysis report

Static analysis result for SHA-256 c0efc4f5558a64d7…

MALICIOUS

PDF

77.3 KB Created: 2021-09-17 16:48:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: c19dae4ef7fd4d0a4286dc1f1bc20980 SHA-1: 12228e39e52b4416733cb226a5774bad66d82efc SHA-256: c0efc4f5558a64d7f3a3c2e7d89715fcb2cff59505bc24fd970b992f7df7f20e
96 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to numerous other PDF documents hosted on various domains, several of which are identified as potentially compromised CMS upload locations. The ML classifier strongly flagged this PDF as malicious. The presence of multiple external links, some leading to potentially malicious content, suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://dainichiji.com/upload_ckr/files/33909963727.pdf In PDF document text
    • https://emotionalgift.com/ckfinder/userfiles/files/71627539694.pdfIn PDF document text
    • http://radtel-sport.pl/userfiles/file/38561341496.pdfIn PDF document text
    • http://kbchina.de/upload/48152028354.pdfIn PDF document text
    • http://www.ssc-ras.ru/ckfinder/userfiles/files/96305436527.pdfIn PDF document text
    • http://szerecsengyogyszertar.hu/editor_up/92540711811.pdfIn PDF document text
    • http://herve-coiffure.ci/files/gagagufisawovata.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613c1aa580c10---36543633370.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613f539e784ca---kufedem.pdfIn PDF document text
    • https://valubil.com/public/uploads/cms_file/cms_files/jifowojupusarud.pdfIn PDF document text
    • http://obchodsezlatem.cz/upload/files/liwuwibige.pdfIn PDF document text
    • http://consorzio-csa.it/userfiles/files/zozanisunekixudo.pdfIn PDF document text
    • http://szjwwj.com/userfiles/file///44079357648.pdfIn PDF document text
    • http://youngdongtec.com/userfiles/file/zajoteruvifozot.pdfIn PDF document text
    • http://rungruangsteel.com/public/upload/userfiles/files/71557687616.pdfIn PDF document text
    • http://talk200.com/admin/admin/uploadfiles/file/60370868564.pdfIn PDF document text
    • https://kalyna.ua/sites/default/files/userfiles/file/pajomejezivomugidabuna.pdfIn PDF document text
    • http://weiken-rc.com/upload/files/fezapevedofanizosaj.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614232886202b---80775886476.pdfIn PDF document text
    • https://gtselect.fr/ckfinder/userfiles/files/2576334613.pdfIn PDF document text
    • http://kyochonbuenapark.iorderfoods.com/uploads/files/71350272558.pdfIn PDF document text
    • http://teaterskolen-efteruddannelsen.dk/ckfinder/userfiles/files/65085553962.pdfIn PDF document text
    • http://savytrading.com/userfiles/file/93147427186.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=john+wick+2014+english+subtitlesPDF 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_off0000c990.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC990 17144 bytes
SHA-256: ba53fe3d02c8e618cf3fa4c742bdc10d1d37f55afab871fe046201049ec1049e
font_01_sfnt_off0000f5ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E06 11028 bytes
SHA-256: 25bd729066a3fbe805bcd0ac67451d89778f2673180aa98a08ecf24636d78cd9