Malicious PDF — malware analysis report

Static analysis result for SHA-256 e79f28fb2e38aca4…

MALICIOUS

PDF

86.2 KB Created: 2021-09-21 04:16:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d43d9f9f05a07e9802c3360e12ec1e46 SHA-1: 898e2770f6c589481ee6243346c50cab04885808 SHA-256: e79f28fb2e38aca4a29d5cc04309c845532a6952704efc55c4fbdc77c5aa719e
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many URLs pointing to compromised WordPress uploads and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The document body was unreadable, but the presence of numerous external links is indicative of a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://caythuocnam.org/images/files/sufapinakubofunivomufesi.pdf
    • http://vevo.keresztessyoptika.hu/elemek/file/96843309454.pdf
    • http://gamecoast.by/uploads/files/499749334.pdf
    • http://daechienglishpark.com/ckfinder/userfiles/files/serubonada.pdf
    • http://csa.china-led.net/static/editor/ckeditor/ckfinder/upfile/files/sidimixanomukerisogu.pdf
    • https://hopadive.cz/ckfinder/userfiles/files/27885288252.pdf
    • https://shellserva.nl/docs/Image/file/buvixenulevuzewenixirek.pdf
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134519e7d7a9---bikabisupovixijuv.pdf
    • http://atdawnwelift.com/userfiles/file/zemafuviwuriliwukigaku.pdf
    • https://jills.reviewz.eu/app/webroot/files/userfiles/files/61541573463.pdf
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/bc14ff32112d77091d2615f152b15034/gesuripadojowozo.pdf
    • https://tavcam.com/upload/ckfinder/files/24009403612.pdf
    • https://jeevandeepspecialcare.com/ckeditor/ckfinder/userfiles/files/sosapurexit.pdf
    • http://laptopcuhaiphong.vn/upload/files/45295383647.pdf
    • http://kondicionery-vidnoe.ru/upload_picture/file/28475923832.pdf
    • http://mitchelllawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/71968957159.pdf
    • http://needychild.org/ckfinder/userfiles/files/48025481357.pdf
    • https://nevisnews.com/userfiles/82943053494.pdf
    • https://inprovitperu.com/ckfinder/userfiles/files/nizokufiw.pdf
    • http://diadiemvui.com/upload/files/ranobasamorem.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/8pd2ke3ecfe707pmptnmontej1/76494622533.pdf
    • https://castel.ro/userfiles/file/89770621091.pdf
    • http://dishandspoonproductions.com/ckfinder/userfiles/files/23596314212.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=create+android+app+using+react+native
    • 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_off0000e9a3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE9A3 16792 bytes
font_01_sfnt_off000101ba.bin
c338468025bbc657fdfea55ed8a69471437047b74c86c15f8f93d7a92fdd94dc
pdf-font-stream PDF embedded font (sfnt) at offset 0x101BA 10840 bytes
font_02_sfnt_off00011ab4.bin
472fce28c9cdc25bd3338a95d487c2dfe910b387ce666b538dff65e30fdfe1f0
pdf-font-stream PDF embedded font (sfnt) at offset 0x11AB4 18648 bytes