Malicious PDF — malware analysis report

Static analysis result for SHA-256 21ad217640cde07b…

MALICIOUS

PDF

86.9 KB Created: 2021-09-03 22:52:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 9b0d32e49e23132bcaed597a4e300bb7 SHA-1: 3226cd26ed74dd51cd20a5afb6f2580010e7eb57 SHA-256: 21ad217640cde07baa51464a0ba0d1b6f52ebceebc3785ab093ffc19277273c4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised or disposable hosting, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to download and execute a second-stage payload. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics reveal.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://allytemp.ru/uplcv?utm_term=trigonometry+table+for+class+10+pdf PDF link annotation
    • https://edusfera.pl/upload/file/46865273554.pdfIn PDF document text
    • http://swotaweb.com/img/upload/file/fowalefukaxi.pdfIn PDF document text
    • http://massageindex.nl/images/uploads/74172687246.pdfIn PDF document text
    • https://spaslask.pl/wp-content/plugins/super-forms/uploads/php/files/8d1ag23nqsla1vgfmee3sr2rn0/30285057921.pdfIn PDF document text
    • http://speakingaboutnetworking.com/ckfinder/userfiles/files/78497376511.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d3cd1cb2d8---59348327856.pdfIn PDF document text
    • http://www.gesas.it/media/mailinglist/file/93609860846.pdfIn PDF document text
    • https://almondzwealth.com/administrator/imagetemp/file/pofowovubanepezilerix.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///kegibuwuwam.pdfIn PDF document text
    • https://www.paparazzirestaurant.com.au/wp-content/plugins/super-forms/uploads/php/files/83859263d46370b89da5222232d4bcb3/zemusidovesutativovowena.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1606d16b75773d---97110532997.pdfIn PDF document text
    • https://thucphamtruongxanh.com/Upload/files/jatiwutozudedejilax.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/nanakuzaza.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bb783c4053c---zetupebanex.pdfIn PDF document text
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/16a244c5946c0eb7de40194bf02ea531/72821035309.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/51fa6c10d57dc25eedeb8c9fd820d2de/26100929124.pdfIn PDF document text
    • http://minhledtran.com/luutru/files/jororupebovikirawibibupov.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160c8cf661d2ad---pesovoxudatedale.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9c113ef981---nakager.pdfIn PDF document text
    • https://xn--bankkrtya-41a.hu/js/ckfinder/userfiles/files/90356242710.pdfIn PDF document text
    • https://www.jscorporation.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/16092819d469ef---10143893730.pdfIn PDF document text
    • http://centreforeffectivecoaching.com/media/file/legona.pdfIn PDF document text
    • https://dacinsara.ro/fckfiles/file/jadowosipavepozaju.pdfIn PDF document text
    • http://taketty.xyz/js/ckfinder/userfiles/files/96384741109.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_off0000e407.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE407 21752 bytes
SHA-256: 46ed562adb28ce3a68dfa8a8b8eb94c975d49eb9317fa6f8155956234e24b3ac
font_01_sfnt_off00011b6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B6A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013381.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13381 11356 bytes
SHA-256: b3843692d66d0b41fe476bc5d05355248b1ce10665361ec56e59fdea842f5ef5