Malicious PDF — malware analysis report

Static analysis result for SHA-256 881d683c084e76cf…

MALICIOUS

PDF

78.1 KB Created: 2021-06-14 06:57:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 85e61000c9db1f91dd53359619e7cbb8 SHA-1: d9b1802ce4e76a26705752c5c63fbc74c18c99f8 SHA-256: 881d683c084e76cfefbcbd44e9d6582b94ddb72fc992a26606ac8afdd3bc8bd5
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm or phishing lure. The document body, though heavily obfuscated, appears to be a disguised attempt to present itself as educational material to trick users into visiting these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • 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://krisoc.ru/uplcv?utm_term=multiplication+worksheets+grade+2+word+problems PDF link annotation
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/ko0jkj91506jajfgb49locqb3k/sogodonezirup.pdfIn PDF document text
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bdd21c44234---nusutes.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1607f299c65381---dipinofizuvegoweden.pdfIn PDF document text
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160960edb33375---91938468965.pdfIn PDF document text
    • https://people11people.gr/uploads/File/zapepivujej.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b6f9c359ab---bopupiwufomogerilasuwe.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b99d9d96fd8---jabijevopaw.pdfIn PDF document text
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/k1t2lbca6fh94lda8u4uekevrj/4536324289.pdfIn PDF document text
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609057fba754c---70718802366.pdfIn PDF document text
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/vj7lmhctq1dot8iij7igaea03k/midolibol.pdfIn PDF document text
    • http://atut-biuro.com/uploaded/file/57002002859.pdfIn PDF document text
    • https://prtl.pl/userfiles/file/deduvibikixav.pdfIn PDF document text
    • http://bbpcosmetics.com/admin/upFiles/2021-6/file/61713963189.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a9b768bff9---nimozozeduvusositax.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093670ad5e08---55776112779.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eeab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEAB 5920 bytes
SHA-256: 1d5d224facd3f34162b1fc8aac9ce0deb1969da39f21d7ad691594da2ad24bd3
font_01_sfnt_off000102be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102BE 11232 bytes
SHA-256: 7be17c4c5a3d763808d187a27762cd54d515add137fa04e0cbae4bbe417d86ee