Malicious PDF — malware analysis report

Static analysis result for SHA-256 77bc7701dbf44c21…

MALICIOUS

PDF

76.5 KB Created: 2021-09-19 01:30:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: f9b74b96222a9c13700335ab8053fcdb SHA-1: 0164bf4f3fbf4d93ebd4c5ed73364baacb99968a SHA-256: 77bc7701dbf44c21a61a4fccbb57d1137fa9b5187c3a8d273f0ffb1f9110d386
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs that form a link farm, with many pointing to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the structure suggests the PDF itself is designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 6

  • 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.
  • 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://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f0ce19e5aa---49813330382.pdf In PDF document text
    • http://rasmesafar.net/basefile/basefiles/fodonemaxosaxivimokem.pdfIn PDF document text
    • http://smeeing.com/userfiles/files/rexulexugikele.pdfIn PDF document text
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/7921f9842675ff5d01adffd4379c4e90/nosen.pdfIn PDF document text
    • http://nfc.soo.jp/file/legupemededigawulibaz.pdfIn PDF document text
    • http://mqskin.com/luutru/files/55086304390.pdfIn PDF document text
    • http://sh-ruiyangcpa.com/userfiles/file/2021-9///2021931819277271.pdfIn PDF document text
    • https://mehreganimaging.com/images/upload/files/rimikena.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/83824119174.pdfIn PDF document text
    • https://kaowei.tw/image/files/20210901_195151.pdfIn PDF document text
    • https://anjingliar.com/contents/files/sizin.pdfIn PDF document text
    • http://talesma.com/E/file/30684701410.pdfIn PDF document text
    • http://spellenindex.nl/images/uploads/13438741919.pdfIn PDF document text
    • http://aptekarynek.pl/zdjecia/fck/file/92556448722.pdfIn PDF document text
    • http://maynenkhiinverter.com/media/ftp/file/silozifesiwekikelivejases.pdfIn PDF document text
    • http://dealershop.es/camarasegovia/userfiles/file/62123380316.pdfIn PDF document text
    • http://seoulgreeter.com/userData/board/file/83406422589.pdfIn PDF document text
    • http://fantasymusic.it/userfiles/files/wamofolanawukedap.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145971073415---zirovidojid.pdfIn PDF document text
    • https://dutchfansitenetwork.nl/ckfinder/userfiles/files/dulig.pdfIn PDF document text
    • http://criollo-cocoa.com/userfiles/file/27649838457.pdfIn PDF document text
    • http://oumkua.com/userfiles/file/5430612275.pdfIn PDF document text
    • http://xfswchem.com/upload/files/86635754292.pdfIn PDF document text
    • https://tiguan-wiki.ru/file/13115363192.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=dualshock+4+otg+androidPDF 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_off0000c7bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7BF 17340 bytes
SHA-256: 0946945862cb514968fe0444a13c5adbcd1d6ab422d891e7b4b109e759472b4e
font_01_sfnt_off0000f3f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F3 10788 bytes
SHA-256: bfbbf9d9fa7563debf6cc4631541ad9fec35271721a487a55905dfe4708eccc8
font_02_sfnt_off00010c96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C96 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1