Malicious PDF — malware analysis report

Static analysis result for SHA-256 b27b51f58fd13da6…

MALICIOUS

PDF

73.4 KB Created: 2021-09-23 09:26:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 24644810b527b79a29646e9ce257f39d SHA-1: bc0a14beaa47bf6896c7ffe69480e33ecfa4d266 SHA-256: b27b51f58fd13da62760dc36f98a5b5e560ef5748f639ea8b32997301980c03d
164 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many pointing to compromised CMS upload directories, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of a 'download button' heuristic further supports a lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://pistant.ru/uplcv?utm_term=apk+day+clash+of+clans
    • http://saikunghouse.hk/userfiles/72748937363.pdf
    • https://onlineadda.organicemall.com/ckfinder/userfiles/files/34223266169.pdf
    • http://bbmpva.nl/fckassets/file/16840750912.pdf
    • https://www.willmarshelter.com/ckfinder/userfiles/files/vapelanipitok.pdf
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1614096d1744f8---tawajowolafetusuxokuvebin.pdf
    • http://jandebruijn.com/uploadimages/files/tovuleribirisi.pdf
    • http://artkulinaria.pl/sites/default/files/file/fosemagegolonis.pdf
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/sqbi62mh0u73d49iojo5qi8ps5/9119769375.pdf
    • https://patc.fr/imagesfile/21574959352.pdf
    • https://www.milestonesmn.org/ckfinder/userfiles/files/devidijuwulerudeb.pdf
    • https://festival.bg/fckeditorfiles/file/zusabepoxun.pdf
    • http://cnsgawefgl.netsociality.com/upload/files/wepetesivuvog.pdf
    • https://soccerauquebec.com/userfiles/file/misurevamunaganadu.pdf
    • http://kurskodkb.ru/page_edit/_samples/userfiles/files/30627538113.pdf
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1614359d12c1a0---susufemubasutixa.pdf
    • http://laxycoffee.com/upload/files/93550064661.pdf
    • http://sportsbettingconsultants.net/cote_dor_import/admin/ckfinder/userfiles/files/90690352735.pdf
    • http://pokeocncafe.com/uploads/files/47222801749.pdf
    • http://goang-hann.com/uploads/files/202109210855345669.pdf
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/16147aad6277f7---87904613800.pdf
    • http://s2group.pl/userfiles/file/60116850009.pdf
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/3a88d1ea16db8533fc85b2552046ba27/90840324523.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_off0000beb2.bin
8d3b414e52c97e440a9b7ce6b8c3813678a2269c69891807cf1ad207cf6060b2
pdf-font-stream PDF embedded font (sfnt) at offset 0xBEB2 10480 bytes
font_01_sfnt_off0000d680.bin
ccfa447df21179e26014fa7440df02fb3e2d2b0d74a81dfef11992aa10a349bf
pdf-font-stream PDF embedded font (sfnt) at offset 0xD680 16252 bytes
font_02_sfnt_off0001004b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1004B 16792 bytes