Malicious PDF — malware analysis report

Static analysis result for SHA-256 41b09c3cb319b0f0…

MALICIOUS

PDF

97.4 KB Created: 2021-08-09 04:26:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 40f21950997c03284757345dfc2687ee SHA-1: 5a384ebf412d882a1f002053fe47ecc7dcb2a940 SHA-256: 41b09c3cb319b0f0e1d8248c78e2ede2b54422c91408cce948366cda8c189fbe
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to compromised CMS uploads and disposable hosting. These links likely serve to redirect users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9959

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 http://air-con.ru/upload/files/64564609882.pdf
    • http://farmaciacogliate.it/userfiles/files/51649403830.pdf
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16096d2daa895f---29920811628.pdf
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cf5b3ca21ca---xedoj.pdf
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160872a9a199b0---81989233596.pdf
    • http://enjoyisagenix.com/ckfinder/userfiles/files/35330271782.pdf
    • http://spreewaldatelier.de/img/editor/file/monoto.pdf
    • http://aydinservis.com/ckfinder/userfiles/files/73343209730.pdf
    • http://www.greddy.com/admin/common/ckfinder/userfiles/File/xojupusirigajin.pdf
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/3ed28f7ffcc5aaf1d2ddb07502e29752/95214466626.pdf
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1609520407ad02---34631042628.pdf
    • https://iaetindia.com/ckfinder/userfiles/files/wonisoguboliziru.pdf
    • https://thewaves.net/wp-content/plugins/super-forms/uploads/php/files/mcrov319lfqh81bf9q7tc2ssop/vopodore.pdf
    • http://citywideok.com/clients/75789/File/bitojixabijafomukowuwis.pdf
    • https://theloneranger.tv/clients/loneranger/ckfinder/userfiles/files/78441202401.pdf
    • http://celyroknaterase.sk/editor_uploads/system/files/73107662227.pdf
    • https://mbamantra.com/ci/userfiles/files/zewazada.pdf
    • http://bjhtdszdh.com/v15/Upload/file/20215222152563521.pdf
    • http://studionegro.net/userfiles/files/vudazugolojanevulesipovaf.pdf
    • http://stevis.cz/files/file/85932059822.pdf
    • http://changrung.com/ckfinder/userfiles/files/maselane.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=control+universal+steren+codigos+para+tv+sony
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f959.bin
afac2f70e72736b4b18f7fc53bd43b7003cb1dc7c077d016d36afb74b1042de4
pdf-font-stream PDF embedded font (sfnt) at offset 0xF959 16096 bytes
font_01_sfnt_off00010ea3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10EA3 16792 bytes
font_02_sfnt_off000126b5.bin
63d546fae97f6440168ae8e1c4baf1da83ed06f33c561026110a40fa164a00a5
pdf-font-stream PDF embedded font (sfnt) at offset 0x126B5 20828 bytes
font_03_sfnt_off00015ade.bin
0161224d791dbe0007b1957f57d665deb5125e6076897b3cd6c01de7be599932
pdf-font-stream PDF embedded font (sfnt) at offset 0x15ADE 11000 bytes