Malicious PDF — malware analysis report

Static analysis result for SHA-256 90d903a2a2b11cc6…

MALICIOUS

PDF

83.4 KB Created: 2021-07-01 15:59:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c4275dea2f4f919fe8da49601b7634c4 SHA-1: 6f60690c968fd334966db704490ba95d7989d604 SHA-256: 90d903a2a2b11cc6a492bb408221418e7728bf4524f6c5f7dd0124ff32d9de2e
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm. Some of these links point to compromised CMS upload directories, suggesting an attempt to host malicious content or redirect users to phishing sites. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://phuocthuan.vn/images/pic/file/4027715403.pdf
    • http://ellissi.org/userfiles/files/95804927736.pdf
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d62ec473aa---rirofo.pdf
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b8ff5681b54---81199870707.pdf
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/5r84b2n9pa0dfprg6vmobaivl7/jupeninovaga.pdf
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1607a1618c2a6a---75258443078.pdf
    • https://tomclarkvoiceovers.com/userfiles/files/47074783705.pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/7ofvs11nu2i8skdpbalavcnpna/dipoliponidabujozoxok.pdf
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d641005c567---5816246514.pdf
    • https://www.zaantraining.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608dd65a44530---88294576076.pdf
    • http://iberia-ex.com/images/blog//file/lerubemefeliv.pdf
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160c96f294ea63---pirepekizagisowusu.pdf
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1609061c46bfff---79115473371.pdf
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc5eea8e05f---80338208029.pdf
    • http://naturallabs.de/userfiles/file/6061863519.pdf
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16087c2b8b3c2e---sixobenexabafuvido.pdf
    • http://belst.by/upload/file/siwagututudisasaturamogi.pdf
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e2b4004034---ribuxiwebofiga.pdf
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/vreooskevhdftsmar4i2ihe4a7/16292822907.pdf
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/2dbf7dd68d52780783023ae5482ff9b5/fuladupu.pdf
    • https://poolpoint.be/uploads/file/2982932544.pdf
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1609aeea3a2bd2---47216529880.pdf
    • https://wtmasonry.com/ckfinder/userfiles/files/62129248952.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=algebra+nation+section+7+answers
    • 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_off0000def6.bin
ee1a4acf1f10b497f353654d0ef3467abb1099eb9af73fcf4f5e8120ba1a0430
pdf-font-stream PDF embedded font (sfnt) at offset 0xDEF6 17856 bytes
font_01_sfnt_off00010e20.bin
7dda423d6d5da6b11309ebedddb540547e2083a2cd6aaadc1e44fdd9bf3317ff
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E20 10660 bytes
font_02_sfnt_off000126d5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x126D5 16792 bytes