Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3eaffa1e41ae5cf…

MALICIOUS

PDF

96.3 KB Created: 2021-09-08 00:07:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a3c164b53efb5e3dd149692789f8eb79 SHA-1: 65fc9f3ba087e25c055464f3a8c1d3bfbaacc3cf SHA-256: a3eaffa1e41ae5cf760eb2556ded22ccf956c8d52f578110d25814bb1a87f208
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' confirms the nature of the document as a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b926c8373a8---54584566638.pdf
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/8v38eta40atlnjsu6tku801s43/92839702043.pdf
    • http://hoanggiaphatland.com/uploads/image/files/lovekeda.pdf
    • https://acavacecio.it/userfiles/files/4729954061.pdf
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160750305987a4---jovuporixuvi.pdf
    • https://bandai-k.com/userfiles/file/94786974473.pdf
    • http://szao-spb.ru/images/news/file/58091312161.pdf
    • http://veterinariacasettamattei.it/userfiles/files/tubotevozu.pdf
    • http://kedehg.com/ckfinder/userfiles/files/defurofovuminaxunefeteni.pdf
    • https://die-elke.de/cms/elke_page_files/file/rutubekukego.pdf
    • https://bharatiyabhashaparishad.org/ckfinder/userfiles/files/37295633615.pdf
    • https://mimpishio2.net/contents//files/33259650939.pdf
    • https://menu2uplus.com/images/file/23872226590.pdf
    • https://talaa-obour.com/webmisr/uploadwebmisr/file/rumip.pdf
    • https://pmcp-avac.com/files/upload-ckfinder/files/3593911452.pdf
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/de6a3c59ea3246c95de5d53ce426e699/xedonu.pdf
    • http://paynechapelduquesne.org/clients/9/9b/9b910c66cef3ae2d1bb1fd5804160a19/File/21545905079.pdf
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f2e0db93ba8---wezabawoburawufoboduzu.pdf
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/4d8995e39312e4b3b1b6c0456bab7cae/rosop.pdf
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/160723b350c3d0---63437979598.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=signo+de+psoas+pdf
    • 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_off0001100b.bin
49c2438fd6be556ae42a1fc275410cfb34646b518bc8c829f312d09c1f19eb91
pdf-font-stream PDF embedded font (sfnt) at offset 0x1100B 10504 bytes
font_01_sfnt_off000127cc.bin
311fbf0c58f6229d68e75d0932e5c040a06809a73eb3dcb328f910187fb42340
pdf-font-stream PDF embedded font (sfnt) at offset 0x127CC 20176 bytes
font_02_sfnt_off00015c24.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15C24 16792 bytes