Malicious PDF — malware analysis report

Static analysis result for SHA-256 f41d3f238ed77a3a…

MALICIOUS

PDF

74.5 KB Created: 2021-09-27 08:23:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: e8dee4dcce910fb3b10d658e9104d642 SHA-1: 79053a838d9c76784ff02856653d4e88a4cf6353 SHA-256: f41d3f238ed77a3acc278e95ac648cb949f70b4878e5087eb3c48b1db31ba18f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior. The document body is heavily obfuscated and appears to be generated content rather than user-readable text.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://123flower.doweb.kr/upload/files/12119894632.pdf In PDF document text
    • http://3gr-group-com.gbintl.com/ci/userfiles/files/63670767014.pdfIn PDF document text
    • http://vinhthuan.com/upload/files/tatixotis.pdfIn PDF document text
    • https://kltccompany.com/ckfinder/userfiles/files/64642490249.pdfIn PDF document text
    • http://residencelesaline.it/userfiles/files/75982831237.pdfIn PDF document text
    • http://kyochonbuenapark.iorderfoods.com/uploads/files/37661505375.pdfIn PDF document text
    • https://cope.lk/assets/media/file/mosesugumovike.pdfIn PDF document text
    • http://www.festivalmarrakech.info/wp-content/plugins/formcraft/file-upload/server/content/files/16139bf82937bb---7190280322.pdfIn PDF document text
    • http://warmistore.com/userfiles/file/97286059742.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/n8jnv52iv9iej9ttsegh0c2ii8/26068818790.pdfIn PDF document text
    • http://areopag-group.ru/sites/default/files/uploads/4083752803.pdfIn PDF document text
    • https://ssekolkata.com/ckfinder/userfiles/files/mosub.pdfIn PDF document text
    • http://megalabsrl.it/userfiles/files/80960108371.pdfIn PDF document text
    • http://teusz.pl/UserFiles/file/97484804877.pdfIn PDF document text
    • https://xn--interpeas-r6a.es/upload/files/67540718182.pdfIn PDF document text
    • http://4x4autok.hu/userfiles/files/82736133460.pdfIn PDF document text
    • http://ahdjcm.com/upload/files/texileletulixekuxobog.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/razewumedag.pdfIn PDF document text
    • http://gyndoktors.de/ckfinder/userfiles/files/peborabiresorijipijutod.pdfIn PDF document text
    • https://zlatartopalovic.rs/files/memoduwuvela.pdfIn PDF document text
    • http://aibrpjoaae2.specialty-match.com/upload/files/mepebod.pdfIn PDF document text
    • http://cuspsurgeons.com/userfiles/file/50847976931.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d20674e2f3---98203683940.pdfIn PDF document text
    • http://fu-xin.tw/uploads/files/202109260123096321.pdfIn PDF document text
    • https://realxenon.ru/uploads/files/13910315849.pdfIn PDF document text
    • http://xtra360.net/campannas/file/50463594794.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=streaming+walking+dead+season+3PDF 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_off0000bbf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBF2 11016 bytes
SHA-256: bd2b7ae161a707406b9243d24c6e58daec8dbe203aa68e0e760b61b751c448e0
font_01_sfnt_off0000d564.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD564 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ed76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED76 17936 bytes
SHA-256: 75a86035aae7dfd3cb23c8d281038fb400346b5a96f7626bf69c780382a958b6