Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f51d8ac139fad10…

MALICIOUS

PDF

81.1 KB Created: 2021-09-09 05:22:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: cbe719fc1891155ed3c4d0850137adfc SHA-1: 8f3b0d00a7d2cb30cac047814987261e9429d716 SHA-256: 9f51d8ac139fad1023d6b266e6ff0bd0ac9d9142b8d4037802a5625ef85c4676
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to domains associated with link farms or compromised CMS uploads, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely involving exploitation of PDF vulnerabilities to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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=more+synonyms+starting+with+p PDF link annotation
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/tunipovebel.pdfIn PDF document text
    • http://faizleathergloves.com/userfiles/files/sudavikukas.pdfIn PDF document text
    • https://kompaspt2.com/contents/files/56463599202.pdfIn PDF document text
    • https://mimpisiluman.com/contents/files/12857963693.pdfIn PDF document text
    • https://hnhaa.com/userfiles/tnejp/files/luzevoxixit.pdfIn PDF document text
    • http://revucue.com/ckfinder/userfiles/files/mojoguju.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/7e155637f1cd13e4baa4bc22a5737077/fugiserowumibavez.pdfIn PDF document text
    • http://coolbiotech.com/upload/files/1463521311.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed7ad25890---57460478266.pdfIn PDF document text
    • https://sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/16135cef0eedce---sironavunoro.pdfIn PDF document text
    • https://marlin-aquarium.ru/ckfinder/userfiles/files/4216765004.pdfIn PDF document text
    • http://xn--80aer5aza.xn--c1acndkmcarx.xn--p1ai/ckfinder/userfiles/files/73617915446.pdfIn PDF document text
    • http://simsvizag.com/contentimages/file/tunivikirage.pdfIn PDF document text
    • http://sunnysolutions.it/uploads/assets/file/mifakewapuwonojikumu.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16130ab64d75c4---25778861156.pdfIn PDF document text
    • http://newtarrytowndeli.com/uploads/files/65259463807.pdfIn PDF document text
    • http://www.farmaciabergua.com/userfiles/files/zidemipesadofasavekibe.pdfIn PDF document text
    • http://jtipartner.com/ckfinder/userfiles/files/gapavuboroxegaj.pdfIn PDF document text
    • http://xn--76-6kca8aqc6c.xn--p1ai/pic/userfile/13668843456.pdfIn PDF document text
    • https://inprovitcolombia.com/ckfinder/userfiles/files/94673005859.pdfIn PDF document text
    • https://deycaterers.com/ckfinder/userfiles/files/93485368908.pdfIn PDF document text
    • http://everest-c.ru/ckfinder/userfiles/files/31195257966.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_off0000d59d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD59D 10844 bytes
SHA-256: c26a6fd005f2e958b12c3fd21a60c21c0ad81b0ac2e3d47f2dc84b8aaa65890d
font_01_sfnt_off0000ee9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE9C 18648 bytes
SHA-256: 5353e987851cb65b45baa9fa5c1e6ac56ba8f9b2cb9609bd1fd0108a19fd8c57
font_02_sfnt_off00011ede.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EDE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1