Malicious PDF — malware analysis report

Static analysis result for SHA-256 451b9d6b0bfd53a1…

MALICIOUS

PDF

76.0 KB Created: 2021-09-01 11:03:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c8a0bd68fb9e2c970c0d755baae0d95f SHA-1: 34f3ae65c2066187bd0b39305b9c52595f34bb45 SHA-256: 451b9d6b0bfd53a1760fbe852a4c0af747923af7b79dea73b187336b76544a2f
156 Risk Score

Malware Insights

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

The PDF contains a link farm hosted on multiple compromised WordPress sites, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or redirection to malware. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9934

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://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160edada56cb86---33115809776.pdf
    • http://voszveszprem.hu/_user/file/budeligegokutagop.pdf
    • http://skpizzasubs.com/uploads/files/6972909938.pdf
    • http://cerescommoditiesltd.com/Images_upload/files/dokoduzolumolu.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a7fa18f00cb---74220881729.pdf
    • https://forcechicago.com/wp-content/plugins/super-forms/uploads/php/files/a6b6831514b172dd1676660d40eb8f47/vodozewomegarux.pdf
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/b3d1df86115080e1502318a10c1fe1f5/givofevivuwalufowajapetow.pdf
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/a97483a790136fb667224067ba99a639/disiduwadoramoxebim.pdf
    • https://stoneappeal.in/FCKeditor/file/guruzidemad.pdf
    • https://remoteyourstaff.com/calisma2/files/uploads/rimakevatodoj.pdf
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/kafogn0tvnpua400j73ricsk76/jixiwojubopi.pdf
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9146cc21f8---87396162790.pdf
    • https://www.rekalibracija.com/wp-content/plugins/super-forms/uploads/php/files/ae6f2b38876af6fb9107418236e697c2/1404919353.pdf
    • http://sklepjola.pl/userfiles/file/pofusilururupikimugozutiz.pdf
    • http://sqc.jp/user_data/editor/ckfinder/core/connector/php/upload/files/ziloziwaxebilewofox.pdf
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4a0060a0df---6879836181.pdf
    • http://lab4050.com/upload/editor/file/fasitesalupamuxa.pdf
    • http://giaydantuongphongngudep.com/images/news/file/31584134642.pdf
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d8d2d3062d0---begosonoduvuwu.pdf
    • https://stl-log.com/htdocs/cljr/data/files/gexumamuxive.pdf
    • http://gewoongroen.eu/app/webroot/files/userfiles/files/vatuxa.pdf
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0f48b5fe49---55584287116.pdf
    • http://www.ks-zahnarztpraxis.de/upload/files/66574434934.pdf
    • https://xn--fiqa735be48e.com/upload/files/39229827566.pdf
    • https://terravistahometeam.com/wp-content/plugins/super-forms/uploads/php/files/d2c25f6ed0c3851461deac9f9ff5ea4b/numomov.pdf
    • https://lepjunk12.hu/uploads/files/97666519509.pdf
    • http://indigobaby.eu/upload/files/42205551194.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=flirt+meaning+in+malayalam
    • 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_off0000c7b9.bin
1b389d868a89c5e2c1860005ff8deba5045254a4a284524383fa205a29e52f61
pdf-font-stream PDF embedded font (sfnt) at offset 0xC7B9 10252 bytes
font_01_sfnt_off0000deb3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDEB3 16792 bytes
font_02_sfnt_off0000f6c5.bin
236f9966e4ccfe50a9d838ecf5816bfce5c775441837aece4d3d9b7f790cd0d2
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6C5 16804 bytes