Malicious PDF — malware analysis report

Static analysis result for SHA-256 a136a611c36b2a75…

MALICIOUS

PDF

72.8 KB Created: 2021-04-28 07:16:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 835fb1f816aae8198bcd24a1e1310893 SHA-1: a84ac48ea57bb3101225b56a139ae7d052d2d46f SHA-256: a136a611c36b2a757f1a8e01a6a013deba3f87262fc2cd76102cfb68cbf7fafd
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious. It contains numerous links pointing to compromised WordPress upload directories and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports its malicious nature. The primary attack pattern involves exploiting user trust through a seemingly legitimate document to redirect them to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/02f4301e32895258978385b3b68988b1/89554090505.pdf In PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/sgj66iv6kfk5sllk1t2uuem4c3/97999769429.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f1ae5b8d7c---nudumupijoludodo.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/16087d6e407c93---gazuraleradepivovofe.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160717af392ff1---rusowatitekixu.pdfIn PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086d1d519052---mafotumojowusavaxadujo.pdfIn PDF document text
    • https://acornschoolcharleston.org/wp-content/plugins/super-forms/uploads/php/files/ac32e604c802dc839539d20e6e13ef07/36844316629.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607a79dca450f---diterafupebuzezedazojap.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/dde6f2a84b25ed563f6dafa05945b402/94629840491.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/4d7c7dc0fcc0e5484e83b7b5e6d2a315/xizevubapubovenewip.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/3aff90307790e61ff795563df1cb0eae/33131350547.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f21c4a24c8---kawuk.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/auugofifv9ahbfdhpdpsgn7fq5/wumezot.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=asme+y14.+5+pdfPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ddf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDF2 5236 bytes
SHA-256: 4fa468c999e39d8a88fe2fcaddde57c8558a7ad19f0752d321ee4b496d025aa1
font_01_sfnt_off0000efdc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFDC 11412 bytes
SHA-256: 820e2cfc645707d093382fcf941fea2fba00d99c6302da09e128484d40598e25