Malicious PDF — malware analysis report

Static analysis result for SHA-256 637878706ae7d97b…

MALICIOUS

PDF

91.7 KB Created: 2021-09-10 00:36:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: c6a9dc82653c9f97c82e755c4ac156e1 SHA-1: a56bf869d9fad12a8e233fc359022c4bc7b3df0e SHA-256: 637878706ae7d97b57d9526943e1b3e973f02e0d6fab942481805adeada5f1b7
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to domains flagged as potentially compromised or disposable. The ClamAV detection and ML classifier strongly indicate maliciousness, likely related to phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document's purpose is to create a link farm, potentially for SEO manipulation or to host malicious redirects.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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 http://avtosfera28.ru/userfiles/file/68829705794.pdf In PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139eda4c17dc---9931459340.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138c7b04115c---61206911092.pdfIn PDF document text
    • http://randoquad72.fr/userfiles/file/14821516775.pdfIn PDF document text
    • http://max-metal.pl/gfx/file/31832752144.pdfIn PDF document text
    • http://czerwoneiczarne.pl/files/file/64073764977.pdfIn PDF document text
    • http://cwesp.biz/upload/file/6878846109.pdfIn PDF document text
    • https://mrdak.cc/uploadfile/files/29444756854.pdfIn PDF document text
    • http://palenice.net/obrazky_clanky/file/vikubediroxobab.pdfIn PDF document text
    • https://pristineleather.com/userfiles/file/letokazapobojoxavebul.pdfIn PDF document text
    • http://www.luna1956.com/images/library/File/12863036505.pdfIn PDF document text
    • http://sindikat777.ru/ckeditor/ckfinder/core/connector/php/uploads/files/20534539184.pdfIn PDF document text
    • http://aftp.bg/userfiles/file/41116335747.pdfIn PDF document text
    • http://guss-ex.de/uploads/fck/file/15028129767.pdfIn PDF document text
    • https://yp05.com/_UploadFile/Images/file/mizixonutofedalufib.pdfIn PDF document text
    • https://masihpt2.com/contents/files/26853837774.pdfIn PDF document text
    • http://seattleteriyaki3.com/uploads/files/viwadiwaperesetoli.pdfIn PDF document text
    • https://acp-luxusingatlanok.hu/ckfinder/userfiles/files/petunokelajon.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/71685298978.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613245f224529---mojawivo.pdfIn PDF document text
    • http://xn----7sbakif2a3azdub.xn--p1ai/admin/ckfinder/userfiles/files/46765345282.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=nnenna+okore+medium+of+expressionPDF 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_off0000fe7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE7B 19368 bytes
SHA-256: 4cec213ce6aa2fa708f40d437511c39c98c96ea34f3dca51deb3df3bc81bbb33
font_01_sfnt_off000130f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014908.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14908 10784 bytes
SHA-256: 89a02c482b4bd8b525474f9d6e6bba24ce3638070c2b8b0804853bc864dec965