Malicious PDF — malware analysis report

Static analysis result for SHA-256 866d7a45ef88bbc1…

MALICIOUS

PDF

73.8 KB Created: 2021-09-05 15:56:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: dd0b2b940d1168b042115e2ecdfa3ee9 SHA-1: 0276230dc9bac827a283ee706d5660b73c5405d7 SHA-256: 866d7a45ef88bbc1ea15a9832328cb55105e9dab2501ad9e8e992350c27874a1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to manipulate search engine results for malicious purposes. While no scripts were explicitly extracted, the PDF structure and link farm behavior are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://beiks.info/public/file/nejijesabazumon.pdf In PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f75cbd3b11---buzobujedokuzewixosuw.pdfIn PDF document text
    • http://webhenevents.com/clients/868374/File/lirapo.pdfIn PDF document text
    • https://www.demetagras.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3a3e7572e---6305406318.pdfIn PDF document text
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/62932353850.pdfIn PDF document text
    • http://12shio5.com/contents/files/27651273548.pdfIn PDF document text
    • https://suma.ca/upload/editor/file/78175080682.pdfIn PDF document text
    • http://color-gateway.com/userfiles/file/jibatemamefivatidefu.pdfIn PDF document text
    • http://lycee-elm.org/userfiles/file/1173542850.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160faa2989f692---rovabisetiduwapow.pdfIn PDF document text
    • https://nutricount.cz/UserFiles/File/fivafumijosunafeloguvugo.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/94a255770cf1fa5b6d5a913c7f987c59/xojakuseluzilumunugulijom.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/1609f740db8e34---37065799511.pdfIn PDF document text
    • https://kermoulin.com/userfiles/file/volarapuzevol.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/116ad6588febe743870c53d5f663ca1b/rosuwadolobikuvigiwop.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16093adf3c83e5---sawamumoluxeto.pdfIn PDF document text
    • http://centrons.com/uploaded/file/140915664160cb8c5948d89.pdfIn PDF document text
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/cvh59u3389tq0oe7a5ffs7sd6p/23911211077.pdfIn PDF document text
    • https://yuanfuconstruction.com/ckfinder/upload/files/44476488896.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160753abfec762---50382556834.pdfIn PDF document text
    • http://faurerom.com/userfiles/file/xifofuno.pdfIn PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160744a2e181f4---leloserativej.pdfIn PDF document text
    • http://marklaliberte.com/fckupload/file/93921813164.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/e7dbb67b514379cb838d3f8932a1649c/65647297298.pdfIn PDF document text
    • http://dycelife.com/userfiles/file/torumotogoxaxuxamerikata.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=uttarakhand+government+holidays+2019+pdfPDF 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_off0000bc32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC32 16472 bytes
SHA-256: 19550defce227c485b7be9a551da9996d323e46482fed60a65824fc0545c90a6
font_01_sfnt_off0000e61b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE61B 11684 bytes
SHA-256: 4dadf4698e50ef37eb60933cf73363ba3f27b0903758800b5df4fc3f4fd58bbe
font_02_sfnt_off000101a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101A2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1