Malicious PDF — malware analysis report

Static analysis result for SHA-256 2916e8f67795bd9c…

MALICIOUS

PDF

72.0 KB Created: 2021-09-11 20:29:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: e464a22cff30d1b3ef6244f9b0695184 SHA-1: 8aabbaa3ab87216f099fb83c18b5311b9cf90f51 SHA-256: 2916e8f67795bd9cbe7a83122732f626c46db09eb0db75b670617bbe3eab331b
184 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating XFA form usage and malformed stream lengths, suggesting exploitation. Multiple embedded URLs point to potentially compromised or disposable hosting, indicating a likely phishing or malware distribution scheme. No scripts were extracted, but the PDF structure itself is indicative of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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.
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • 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://smidgel.ru/uplcv?utm_term=the+last+stand+apk PDF link annotation
    • http://www.protectakoteasia.com/ckfinder/userfiles/files/35783250459.pdfIn PDF document text
    • https://nepalonlineexam.tisaracademy.com/userfiles/files/pumopelurajizudaxod.pdfIn PDF document text
    • http://parquet-cortes.fr/data/Files/98630336628.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613590b757f35---tibuxulexavivebomavafe.pdfIn PDF document text
    • https://mkycc4.com/kycc4.com/userfiles/files/47637851721.pdfIn PDF document text
    • http://jmyhship.com/uploadfile/files/4401999818.pdfIn PDF document text
    • https://lose-weight.tw/upload/files/ganesaxesik.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613755cfe1d0a---26092595304.pdfIn PDF document text
    • http://francescasciortino.it/userfiles/files/bisizurelidekinatenujuket.pdfIn PDF document text
    • https://tekdalyapi.com/upload/ckfinder/files/tenogibufo.pdfIn PDF document text
    • http://minhtoangalaxyhotel.vn/app/webroot/files/ckfinder/files/70717326126.pdfIn PDF document text
    • https://implantologie-deva.ro/app/webroot/files/userfiles/files/vesiwusumemozuve.pdfIn PDF document text
    • http://mobilenmr.com/files/files/tozakanitajakidog.pdfIn PDF document text
    • http://kingbikeonline.com/images/upload/File/9875192848.pdfIn PDF document text
    • http://montpellier-businessplan.com/mbp/upload/images/images/upload/ckfinder/15211029703.pdfIn PDF document text
    • http://defhjdrjioo.friend-match.com/upload/files/bagujugivomuga.pdfIn PDF document text
    • http://cu-hinothai.com/ckfinder/userfiles/files/guvotewevunazedejuxinigor.pdfIn PDF document text
    • http://sm.ac.th/ckfinder/userfiles/files/wagubekozi.pdfIn PDF document text
    • https://unitedfightalliance.jordanadams.com/ckfinder/userfiles/files/14047950808.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/455783f1193d7d6665409367ad65b36a/42140912348.pdfIn PDF document text
    • http://qiuyutv.com/userfiles/files/20210906045749.pdfIn PDF document text
    • http://ukwoodrecycling.com/userfiles/files/wedewiv.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_off0000b803.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB803 10232 bytes
SHA-256: d8dca351cc08a1ea50419b65ad9d8f60ffdd62dd24199b658b1af99441aac787
font_01_sfnt_off0000cef6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEF6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e708.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE708 17072 bytes
SHA-256: 7908b1e91a67ff225178fc6e5e76dfbaa082f59804fc7a5f38269a5387562377

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