Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4f259cf925eb575…

MALICIOUS

PDF

71.5 KB Created: 2021-09-03 15:26:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 89553360151b5ef4f9f843dd3deb2471 SHA-1: 84cb0458c6f6e13f50fc96a389a5cb1b0f89d6b6 SHA-256: b4f259cf925eb575641a51a00a74fb9ca9955945de65780ba8b043f0e6da4114
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting. The embedded URLs, while some are marked benign, contribute to the overall pattern of directing users to external, potentially untrusted sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://www.reflectionuk.com/wp-content/plugins/super-forms/uploads/php/files/edh5pg4i2avg7vr0d6vuq4ue31/98554484700.pdf
    • http://mariekevanvlierden.nl/survey/userfiles/files/46010397689.pdf
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/16089a0efcf950---taxatidibewakadevugudit.pdf
    • http://vmkmsz.hu/userfiles/file/kaderozigotu.pdf
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/1606f8349465de---kelixosedutalixigew.pdf
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ecc194fa1cca7158e2347ee900b390ee/61588964052.pdf
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160877b6119d33---41382837602.pdf
    • https://www.foundationofhope.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607f531f6bc1a---mujonisawonipivuremi.pdf
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/xugenamirez.pdf
    • http://frutapac.com/ckfinder/userfiles/files/23352025589.pdf
    • https://sayurhijau.com/contents//files/punajupuzel.pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/iuadmmuq05u8dh2o3krjacf7g7/37194607045.pdf
    • http://cybernet.asia/UserFiles/File/nexonedevesazij.pdf
    • http://kxnjl.com/userfiles/files/jojezoxozegato.pdf
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8ac3aa9880---52749346480.pdf
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/fdbdb278cbcc7018c444b38a27d57843/bilubelodezokanupufutinel.pdf
    • http://tjsijiqing.com/ckfinder/userfiles/files/2021/0720/c67c7703c8bd0010b76e413e872f6d1b.pdf
    • https://olympicwroclaw.pl/zdjecia/fck/file/pefinagoromotawazetefo.pdf
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/8269e36c06354be1426fd281cadccf30/67650709795.pdf
    • http://prattsofdouds.com/clients/d/d8/d85aab9f4bcbae69c8358f7a9990a0b1/File/povawiberavelurujunuvofet.pdf
    • http://asokmontridental.com/userfiles/file/42044657060.pdf
    • https://goodline.by/userfiles/file/texifemizafotewoxi.pdf
    • http://srividyaastrology.com/userfiles/file/41804861436.pdf
    • http://bestbuyfromindia.com/userfiles/file/kidonasilej.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=nephrotic+syndrome+vs+nephritic+syndrome+pdf
    • 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_off0000b910.bin
e6c796faeb44164d1f576159219e2ebd6ece3e1cf0014bcaf7a37cfdee7f7b44
pdf-font-stream PDF embedded font (sfnt) at offset 0xB910 15148 bytes
font_01_sfnt_off0000df19.bin
2cc4b76b4dd5f4d57bf01260e418316ef73e0c1d3192ec2c9739e2b02a8aba9d
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF19 10836 bytes
font_02_sfnt_off0000f7f9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF7F9 16792 bytes