Malicious PDF — malware analysis report

Static analysis result for SHA-256 c35e6ba0563ea009…

MALICIOUS

PDF

87.8 KB Created: 2021-07-08 12:47:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 3a0493b5dd85ba99006b054c6371ca3a SHA-1: e7f22bef66bc265217aa5b8ebe3c1b22128e7c46 SHA-256: c35e6ba0563ea00981aa874cae912fffdece27c64ea512aa5bd384563cbf031c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress upload storage, suggesting a phishing or malware distribution lure. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160acf2a269160---nenakanajomebix.pdf In PDF document text
    • https://beautifullifeuk.com/wp-content/plugins/super-forms/uploads/php/files/0123652f95111a70c0d47f90d7394c25/kobagewewupusiwuberofunuk.pdfIn PDF document text
    • https://vyrukrc.lt/userfiles/file/ruvemovutikijonijase.pdfIn PDF document text
    • http://studiolegaletrotta.eu/userfiles/files/belamajomobutalax.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/u61frnpjd2k6194s42q33h6ru5/42390693081.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087623a81912---lajizoribarivu.pdfIn PDF document text
    • http://nousgarage.com/userfiles/file/12923470130.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082cd460dfc8---nenalawi.pdfIn PDF document text
    • http://orchid-daikanyama.com/userfiles/file/95637673196.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160964c86bd22e---tibosijofufemubabupajujof.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b4c08cb5d77---44871043705.pdfIn PDF document text
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/3d34516dd0d4addb881d9160f6139114/wewunejikanemupas.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab488d78d4f---16175413322.pdfIn PDF document text
    • https://detectiveoffice.net/userfiles/file/63366315622.pdfIn PDF document text
    • http://szao-spb.ru/images/news/file/43570908900.pdfIn PDF document text
    • https://ascinfratech.com/clientprojects/trading/file/dojofafemewo.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16090a946b31f3---48909690450.pdfIn PDF document text
    • https://bechtoldpaving.com/wp-content/plugins/super-forms/uploads/php/files/13609743e9e1b0d2ecca5cab9b14112b/tesifaputatev.pdfIn PDF document text
    • https://www.alpha-dynamics.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16072171d0529b---60811188245.pdfIn PDF document text
    • http://nuestratierrapremios.com/campannas/file/tufotesujezewekavepod.pdfIn PDF document text
    • http://yuhenganquan.com/userfiles/file/20210618033657_735689904.pdfIn PDF document text
    • http://petersonspann.com/clients/3/32/32c4b2f41fa698b5b938e848169c8dcb/File/90478344298.pdfIn PDF document text
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6cb7661d04---sanosikopunu.pdfIn PDF document text
    • https://sitpchemcieszyn.pl/_sitpchem/file/78169344932.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075d02914fa2---71446783665.pdfIn PDF document text
    • http://africa-emergence2019.com/userfiles/file/xonomuvu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=tilda+swinton+the+lion+the+witch+and+the+wardrobePDF 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_off0000f05e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF05E 10656 bytes
SHA-256: a17403246e7a5aeda8621804cd6afa7d8607135d24d6e9dff26e1d1fc832506f
font_01_sfnt_off000108ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108BA 18440 bytes
SHA-256: bb8bafac89efb5122f8d4d45849ebe4cf7a903816bef429c60bca0daad9f4574
font_02_sfnt_off000137b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137B2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1