Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a3921b91ce09ef3…

MALICIOUS

PDF

72.5 KB Created: 2021-09-25 19:13:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 81e9cb84349a138b29e277de3299152c SHA-1: addc38272f982f30aaf98c8bbda2fc6ac5c3f017 SHA-256: 4a3921b91ce09ef34931a634e3f7350b1a54493167f19b739005094fa9748c26
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. The embedded JavaScript is a common technique for initiating malicious actions within PDF documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://samngaimarble.com/html_upload/file/34217490443.pdf
    • https://kocarbon.vn/luutru/files/xonifogekomax.pdf
    • http://hcbarrett.com/user_area/file/16459747968.pdf
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/gp66qlf6dilks53kjn3vcfq7ls/96438688505.pdf
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/d41b802ab4312b631b3e307bcc48b69a/5577769093.pdf
    • http://nhadep30giay.com/uploads/image/files/depiramoruminure.pdf
    • http://macautemple.com/userfiles/file/gupekaranimefekafajojupi.pdf
    • http://eldmsh1.ru/js/ckfinder/userfiles/files/jefunanosovelef.pdf
    • https://pima-alarms.net/slicice/file/gotusegepabujagubatope.pdf
    • http://gdfsztal.com/uploadfile/files/febetubuleziganawadusuxo.pdf
    • https://olterus.com/contents/files/wapilavokeginelepunumereg.pdf
    • http://hotstamping.pl/files/file/76565323976.pdf
    • http://studiosaletta.it/userfiles/files/74155785368.pdf
    • http://casinodanmarkjackpot.dk/userfiles/file/jadobexubug.pdf
    • http://robertwestlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pezunefeduwuxom.pdf
    • http://ardeche.proximeo.com/ckfinder/userfiles/files/73490777689.pdf
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/5a0h5j3hb4puosil1rkgl1a5e1/vevojunifo.pdf
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613e8651a355e---xinisetivemuf.pdf
    • http://ylpqzl.com/ckfinder/userfiles/files/jatuxunaxigudimotob.pdf
    • http://whuntex.info/userfiles/file/34300727112.pdf
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/b1c011e9eb17edb57c3a822bdb78989a/75421824807.pdf
    • http://sanzmendia.com/userfiles/files/wokavuvawakisuguto.pdf
    • http://stuarteisbrucklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lunixoxiwurifoduwuvepo.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=good+recording+apps+for+android
    • 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_off0000b407.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB407 16792 bytes
font_01_sfnt_off0000cc19.bin
5880c4b4d77cef5528baafa1f93b5919cac49fffaf64b8adf9f1eae0cbbf49bf
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC19 18456 bytes
font_02_sfnt_off0000fc08.bin
8f0fb15da0ae1a9c3286424202263bb117acae09a6ac46e5931ec8fa2d465ce0
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC08 10688 bytes