Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4e01fd3db53d281…

MALICIOUS

PDF

84.1 KB Created: 2021-07-21 14:02:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: aa6c3e5cbae158506a9ddfe561055587 SHA-1: ec6cd4d02bdc24000342090d73ebf40a5cb6015a SHA-256: e4e01fd3db53d281f5bf0de1186bea09c6a47580a38da259be5ecd57c1a81058
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a PDF link farm, with many URLs pointing to compromised CMS uploads or disposable hosting. While no scripts were explicitly extracted, the PDF structure and link farm behavior suggest it's designed to lure users to external malicious sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://cucthongke.vn/userfiles/file///wutekuwelu.pdf
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/5a107kgae6455l1ejj6gtbbpr6/1490487523.pdf
    • http://studiocalcinoni.com/userfiles/files/3298757589.pdf
    • http://ahlhy.com/uploads/file/201137296611.pdf
    • https://shreenathtechnologies.com/userfiles/file/95032741031.pdf
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/a10093d8360d0753c227d1d743c2a896/zuwotadin.pdf
    • http://fsgzb.com/upfolder/e/files/20210718004733.pdf
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c15958636db---32380198543.pdf
    • http://hytechplus.com/userfiles/file/lixinebujujofa.pdf
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/21907060d721953f0b360848e970d931/25298176675.pdf
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086510b9fd97---26663577253.pdf
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/feee60a3db9c39dcd2dc269810cc1baf/paveborit.pdf
    • https://amursvoidom.ru/media/files/votobefakexosipasiwo.pdf
    • http://polimak.pl/userfiles/file/boduxisugotudapapinapipaw.pdf
    • http://donghozibistore.com/luutru/files/xazorefinesikaz.pdf
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160e732404a8a6---sipuveza.pdf
    • https://destockbaby.com/ckfinder/userfiles/files/32167773389.pdf
    • http://5m-tti.com/uploads/image/files/mipodigikigepal.pdf
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/5bfd9f50395b150de289d67dc47e6a43/44843104533.pdf
    • https://travelstore.tn/userfiles/file/82092426552.pdf
    • https://mkontakt.pl/dat//file/71431594400.pdf
    • http://scvumaichiramen.com/uploads/files/80675535846.pdf
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160a1974c8dbac---33138313858.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=theme+of+poem+my+mother+at+sixty+six
    • 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_off0000e7be.bin
41e76fb8b3a59bc78b0518081fc6c1941c9681af2ad3396dd9a419091d8aa9b8
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7BE 16636 bytes
font_01_sfnt_off000112a9.bin
556d7c9ea21fea063bbbbe463034f1af172357231c13ac8155c1b2e093b9c464
pdf-font-stream PDF embedded font (sfnt) at offset 0x112A9 10652 bytes
font_02_sfnt_off00012b24.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12B24 16792 bytes