Malicious PDF — malware analysis report

Static analysis result for SHA-256 a087bbd572a6da5a…

MALICIOUS

PDF

77.0 KB Created: 2021-09-08 14:33:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 71f91ec356c5cdc563918126fb473533 SHA-1: 67b747ee3e3b4978437b6e48af78342ec045c7e4 SHA-256: a087bbd572a6da5afeb469ce2cd79cc6d121cfaa0b4bbb419b5d045ce1d99166
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which are hosted on compromised or disposable domains. These links form a link farm, likely intended to redirect users to phishing or malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://philabc.ru/uplcv?utm_term=ncert+exemplar+class+9+chemistry+pdf PDF link annotation
    • https://bohemiamaestro.com/webpagebuilder/ckfinder/userfiles/files/wupar.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130bcacbc3c4---42018221540.pdfIn PDF document text
    • https://vhssirimpanam.org/ckfinder/userfiles/files/2024686190.pdfIn PDF document text
    • https://yptea.com/data/fckeditor/files/gasoba.pdfIn PDF document text
    • http://tinavaron.com/ckfinder/userfiles/files/99514722531.pdfIn PDF document text
    • http://vpsystem.com/files/fck/jiguwukedure.pdfIn PDF document text
    • http://ark-mr.com/data/home/qxu2063190031/htdocs/uploadfile/files/virikegukafupumimofe.pdfIn PDF document text
    • http://waetsukai.jp/system/ckfinder/userfiles/files/69161121161.pdfIn PDF document text
    • http://radiopoint.cz/userfiles/file/38568758477.pdfIn PDF document text
    • http://aczelzalog.hu/tmp/1919101733.pdfIn PDF document text
    • http://hzbmsj.com/images/upload/File/34984625725.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/jl0kami29q82gptimdmvhnu1s5/gasabuvawogajulibuni.pdfIn PDF document text
    • http://www.tokyomagic.jp/images/library/File/ranefiforopidobomejow.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613344aa4ced9---tawekasulapofuwu.pdfIn PDF document text
    • https://ans5680.preneed91.com/upload/files/52896597533.pdfIn PDF document text
    • http://www.reeder.ee/files/filemanager/38647876460.pdfIn PDF document text
    • https://teamcode.net/upload/files/retedujufuporixewotexede.pdfIn PDF document text
    • http://vietsaovang.com/uploads/userfiles/file/10636804249.pdfIn PDF document text
    • https://imahima.xyz/js/ckfinder/userfiles/files/masowafiduxakenufo.pdfIn PDF document text
    • http://boissee.fr/userfiles/file/74233107181.pdfIn PDF document text
    • https://sakkestadbil.no/userfiles/file/13652791253.pdfIn PDF document text
    • http://immobilieninvestors.eu/userfiles/file/36778060063.pdfIn PDF document text
    • 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_off0000c804.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC804 11020 bytes
SHA-256: 075c0603ade857e1fa132f4482d6d4e23c570656c899c86e1a3ffeb4935754f6
font_01_sfnt_off0000e1b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f9ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9CA 17480 bytes
SHA-256: 83f55e6f89fe35e312fb88ea48b9aff1a4a5d2c85d2d35db735cba4125d023ac