Malicious PDF — malware analysis report

Static analysis result for SHA-256 03e50fbf6b8875a7…

MALICIOUS

PDF

80.4 KB Created: 2021-09-16 23:02:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 74e456966b67888342204a94f27996b2 SHA-1: 08de0ee13ce925f4050946e0b5660b950f0499c1 SHA-256: 03e50fbf6b8875a774a9a1a6ef08f79310a5b8773c1c6a7891661283f89ae67d
156 Risk Score

Malware Insights

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

The PDF document was flagged by multiple heuristics as malicious, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. The presence of a link farm, with several links pointing to compromised CMS uploads and disposable hosting, indicates an attempt to redirect users to malicious content. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://jncs.kr/page_data/file/20210901171340.pdf
    • http://herium.net/FileData/ckfinder/files/20210908_E8691F308BED192C.pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614031756325c---31531460293.pdf
    • https://bgg.pirkitpadangas.lt/ckfinder/userfiles/files/lozalosofazomovavilokixej.pdf
    • http://chayka-svg.ru/files/94854527934.pdf
    • http://dangkykinhdoanhkiengiang.com/upload/ck/files/30697212375.pdf
    • https://sonerofset.com/userfiles/file/xomogoviviwepekolowo.pdf
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613dc564e8ab5---mavugisujojifez.pdf
    • https://doucetplasticsurgery.com/ckfinder/userfiles/files/69632103417.pdf
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea14d562f5---xejuvuxolilun.pdf
    • https://www.iieng.org/editor/ckfinder/userfiles/files/digamuzegodipafagomamib.pdf
    • https://koratspring.com/upload/file/97881168936.pdf
    • http://aytekinpolatel.com/image/files/lujabituga.pdf
    • http://ryouhurt.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/89432427085.pdf
    • http://www.jysunshine-hotel.com/up_files/file/dajuvegarik.pdf
    • https://www.leadercaravans.com.au/application/third_party/ckfinder/userfiles/files/felov.pdf
    • http://ipceurope.be/assets/file/55978866109.pdf
    • https://santehsevast.ru/userfiles/files/80186739081.pdf
    • http://xn--9i1b14lwsg1seumdzsx.com/upload/fckeditor/file/39280258074.pdf
    • http://huyndaicaudien.com/upload/files/jitokaxuwezixoras.pdf
    • https://cosonnguyenthanh.vn/webroot/userfiles/files/84036818199.pdf
    • http://wellgroup.cz/UserFiles/File/5788871956.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=excel+app+download+pc
    • 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_off0000d638.bin
d6af13eca77edc079828e8d892f6d9e57476ab346395989b6725e3c4edf23cf5
pdf-font-stream PDF embedded font (sfnt) at offset 0xD638 10220 bytes
font_01_sfnt_off0000ed51.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED51 16792 bytes
font_02_sfnt_off00010563.bin
de1e6254199b6923dc299e348513d7f31c455822575bed46923a067942603797
pdf-font-stream PDF embedded font (sfnt) at offset 0x10563 17936 bytes