Malicious PDF — malware analysis report

Static analysis result for SHA-256 820cf658307268d4…

MALICIOUS

PDF

71.8 KB Created: 2021-10-03 02:50:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: c297960b3b771a5bb19054431859015d SHA-1: c85a7a07ed3abb2e5451cbf67f2258e0f1636de7 SHA-256: 820cf658307268d4366e9fc35928c8757fb2e6110cf0d4e32fcc3fadd4bd2ecb
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, many of which are identified as link farms on compromised or disposable hosting. The heuristic PDF_MALFORMED_EXPLOIT_STREAM_LENGTH and ML_NYX_PDF_MALICIOUS indicate malicious intent, and ClamAV detection confirms this. While no scripts were directly extracted, the structure suggests it's designed to redirect users to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • 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.
  • 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 http://superfishinglewood.com/uploads/files/kosezeredotub.pdf In PDF document text
    • https://misbahelmudii.org/ckfinder/userfiles/files/jageposaboboxosus.pdfIn PDF document text
    • https://triosms.com/userfiles/file/jepolepemetupuvulunilepuv.pdfIn PDF document text
    • http://lesbambousbleus.fr/ckeditor/upload/files/38534495973.pdfIn PDF document text
    • http://ourgans.org/userfiles/files/93431247653.pdfIn PDF document text
    • http://footstepfloor.com/upfiles/files/mufurubasopononowedunorik.pdfIn PDF document text
    • https://soi.icami.mx/ckfinder/userfiles/files/16609835509.pdfIn PDF document text
    • https://zoldlepes.hu/userfiles/file/63332503156.pdfIn PDF document text
    • https://md-bud.pl/szklo/photos/file/kilobezisip.pdfIn PDF document text
    • https://megacook.pt/site/upload/file/mapusemilazifimef.pdfIn PDF document text
    • http://beautybybelief.com/admin/images/file/83239213145.pdfIn PDF document text
    • http://zjbfjt.com/upload/files/73452281718.pdfIn PDF document text
    • https://store-connector.com/_upload_bilder/_filemanager/file/kivetivowefopujugamofojad.pdfIn PDF document text
    • http://wingtsunkungfu.ro/imagini_ws/4795089243.pdfIn PDF document text
    • http://szyoujin.com/UploadFile/file/20211002152238609.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab32dd56f1---37206388870.pdfIn PDF document text
    • https://marblobathware.com/app/webroot/img/files/72897616275.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16140c3015c626---29994480273.pdfIn PDF document text
    • https://chingchia.com/uploads/files/202109231650456245.pdfIn PDF document text
    • http://oodow.cn/upload/file/210905175345759060asob1rl4asgb.pdfIn PDF document text
    • https://petribax.nl/userfiles/file/94451490316.pdfIn PDF document text
    • http://alpes-de-haute-provence.proximeo.com/ckfinder/userfiles/files/71453859589.pdfIn PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/ff8bc4cba80d2db85908b751cbc519c2/85503842811.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16143db4fc2903---61308770404.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=how+to+wake+up+early+in+the+morning+after+sleeping+latePDF link annotation
    • 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_off0000b361.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB361 17332 bytes
SHA-256: 8abbec7bf202224289643ffaa639c8ce6b426f890d59e2a560bfe8770e1062a0
font_01_sfnt_off0000df1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF1B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f732.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF732 11188 bytes
SHA-256: 7b7ed0402f317895b34c60e7ca685d9b567b797a73c9b4a29ca401c3266c653c

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