Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8a9437f6f0ab218…

MALICIOUS

PDF

72.9 KB Created: 2021-10-11 23:14:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 9e761f5da741407b05becd165f22c724 SHA-1: 63680f9bc16da8c71bbee168b221bd29babd832a SHA-256: c8a9437f6f0ab218aae44f0f43875d5da65abf2453afe5fc52d16ef513b229d0
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised websites or disposable hosting, suggesting an attempt to redirect users to malicious content. The document body is heavily obfuscated, preventing a clear understanding of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://rizecanreklam.com/images/file/muvoxemoxono.pdf In PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/takepasijexapesamekuxobi.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ccdf867445---10649226907.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615385156e719---55198800874.pdfIn PDF document text
    • http://rungruangsteel.com/public/upload/userfiles/files/rovafikowavufutajujok.pdfIn PDF document text
    • https://gretajensen.com/ckfinder/userfiles/files/41186052279.pdfIn PDF document text
    • http://xtra360.net/campannas/file/jasuxizid.pdfIn PDF document text
    • https://alusol-kw.com/ckfinder/userfiles/files/32408595919.pdfIn PDF document text
    • https://kcharp.com/ckfinder/userfiles/files/94901353699.pdfIn PDF document text
    • https://sierrainstruments.cn/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/sekegusonitemosulasa.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16162930e61796---piwilifedadofilovewevapew.pdfIn PDF document text
    • https://jeneifogaszat.hu/cikkdata/files/difewaja.pdfIn PDF document text
    • https://detskeihriska.eu/ckfinder/userfiles/files/zugidajakipa.pdfIn PDF document text
    • https://mabuksusu2.com/contents/files/1379474326.pdfIn PDF document text
    • http://musikpark-live.de/userfiles/file/5726876736.pdfIn PDF document text
    • http://zoo-foto.cz/userfiles/file/bevegapimuredasami.pdfIn PDF document text
    • http://mijn-nederland.nl/userfiles/file/wibuzat.pdfIn PDF document text
    • https://legend-chang.com/UserFiles/files/206748151.pdfIn PDF document text
    • http://ambvetbrashersclavoghisu.eu/userfiles/files/bufaxojazujawukegun.pdfIn PDF document text
    • https://afritransport.com/app/webroot/files/file/posufonesusepiv.pdfIn PDF document text
    • https://piphoto.tw/uploads/files/202109110904289939.pdfIn PDF document text
    • http://drapikowski.pl/uploaded/fck_files/file/zuzutu.pdfIn PDF document text
    • https://ovistar-dz.com/ckfinder/userfiles/files/86747980291.pdfIn PDF document text
    • http://kamkmori.cz/ckfinder/userfiles/files/83732830181.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/7xhmvLXWVJc/uplcv?utm_term=low+grade+spindle+cell+sarcomaPDF 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_off0000b9cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9CF 10800 bytes
SHA-256: b208f7d0438401bcaff1e5999575df9ef4718f14836a048e9c3561cb31cfb933
font_01_sfnt_off0000d27c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD27C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ea8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA8E 16652 bytes
SHA-256: 9bb63a444b228e722e3b04c4751e080940af83951b4cdd645d812b68542883fd