Malicious PDF — malware analysis report

Static analysis result for SHA-256 983172401c0535bd…

MALICIOUS

PDF

68.3 KB Created: 2021-09-30 11:52:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6e685c5680ef272d4ab7c9d84990050b SHA-1: 3baba5f0c2e9ddee967138ccd8d3dda9f2d14731 SHA-256: 983172401c0535bd19a3447c74508b7add009ef1d3c96eb58fa29ab2246d5f32
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS upload directories or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document is designed as a link farm, likely to direct users to malicious content. The embedded JavaScript, though not fully detailed, is a common vector for further exploitation in PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://unipsyclinic.com/userfiles/file/20210913224200.pdf
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16151a45f9f6d2---59119769473.pdf
    • https://franciscovalles.comtraining.cl/userfiles/files/fubogujudonixugemud.pdf
    • http://24horasnoar.com.br/ckfinder/userfiles/files/2250131241.pdf
    • http://pk.mo/userfiles/file/5491985200.pdf
    • http://autofactory-jin.com/js/upload/files/60171687146.pdf
    • http://metaglas.kr/userData/board/file/4204937535.pdf
    • https://kolkataangikar.org/ckfinder/userfiles/files/29833945407.pdf
    • https://unitedfightalliance.com/ckfinder/userfiles/files/pavegodamowaterixesi.pdf
    • http://sahrugs.com/userfiles/file/98335439962.pdf
    • http://studiofelician.com/userfiles/files/14828633869.pdf
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/16131aee3914fa---romusarojipoduwovesisuli.pdf
    • http://imhkayseri.com/resimler/files/47528176110.pdf
    • http://www.lbtfilm.com/uploads/files/nefaxemalutemakase.pdf
    • https://artbynela.com/uploads/file/5414939696.pdf
    • http://ezclasssites.com/var/wwww/dev-ezclasssites-com/data/files/libenurovokuzukuselusus.pdf
    • https://onutglen.com/caningest/images/file/55968814854.pdf
    • http://domesticsolutionsagency.com/userfiles/file/85487791355.pdf
    • http://rts-3.ru/upload/files/xetifuvuwigevunigeboban.pdf
    • http://www.fred-robin.com/ckfinder/userfiles/files/56589733126.pdf
    • http://yourbuilding.ru/userfiles/files/77641802438.pdf
    • http://huseyindurmuslar.com/images_upload/files/xigagarakufubolo.pdf
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1614dcd89a032e---refijotinupi.pdf
    • https://mpressivelabels.com.au/application/third_party/ckfinder/userfiles/files/lukep.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=chord+love+story
    • 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_off0000af8b.bin
c490b3a93d57d4fc4e5451fafc13a18aaa6489822e38f69f423fe3b68ba03bff
pdf-font-stream PDF embedded font (sfnt) at offset 0xAF8B 14928 bytes
font_01_sfnt_off0000d50c.bin
4924da8e200fa723481b6da548b503a063a8ca65051a23b5e586e24f3ed2e587
pdf-font-stream PDF embedded font (sfnt) at offset 0xD50C 10196 bytes
font_02_sfnt_off0000ec25.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC25 16792 bytes