Malicious PDF — malware analysis report

Static analysis result for SHA-256 665140ffd8c6562a…

MALICIOUS

PDF

41.9 KB Created: 2020-07-18 04:26:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-04
MD5: f155fdbe084cc85c1594dfde6946dcdc SHA-1: e3a7bae40483e4c013aa7dc1fbf1330ed928777f SHA-256: 665140ffd8c6562ae1750d900c2c781c13d0f940fbb164a93dcc32730c392fea
194 Risk Score

Malware Insights

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

The PDF contains numerous links to external sites, many of which are identified as malicious redirectors or part of an SEO link farm designed to distribute more malicious PDFs. The document body, though heavily obfuscated, contains keywords related to 'persuasion pdf free download' and the authoring application 'wkhtmltopdf', suggesting a lure for users seeking free documents. The ML classifier strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://ttraff.ru/wb?keyword=persuasion%20pdf%20free%20download In PDF document text
    • http://files.greekdressing.net/uploads/1/3/1/3/131380120/tasuxen.pdfIn PDF document text
    • http://files.gilbertparksandrecreationfoundation.org/uploads/1/3/2/7/132740458/jenax.pdfIn PDF document text
    • http://files.humanesocietyofdelnorte.org/uploads/1/3/1/1/131163705/lubonipoxeguxifavel.pdfIn PDF document text
    • http://files.lemonpatches.com/uploads/1/3/0/8/130813362/temavuzugotasepu.pdfIn PDF document text
    • http://files.fulltiltstreetrods.com/uploads/1/3/0/7/130739712/nebolobozis_povimifopodolet_penexoro.pdfIn PDF document text
    • http://files.redtrustbushey.org/uploads/1/3/1/6/131637307/zosakojofutom-gozobosukowemi-joruparod.pdfIn PDF document text
    • http://files.joannapickering.com/uploads/1/3/1/6/131606431/fetexejaliku_bupel_netoledukomek.pdfIn PDF document text
    • http://files.shenfieldlearning.com/uploads/1/3/1/1/131164567/ae3cbc5a8a34cb8.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://bapomen475531298.files.wordpress.com/2020/06/vizinipoludowodok.pdfIn PDF document text
    • https://fiwogomajalo.files.wordpress.com/2020/06/98885462694.pdfIn PDF document text
    • https://sunadasuz.files.wordpress.com/2020/06/kufawe.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/8153/9483/files/16323641331.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/3583/6059/files/39908161694.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/9889/8592/files/56700871984.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/1231/6584/files/furodusekuwexipudawixar.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/0677/0843/files/32191476698.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/59577082877.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0435/2425/9992/files/jibodibogalalosexoxevun.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000674e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x674E 4932 bytes
SHA-256: 7d2628a72e05d40a4a3953c5fb3f4b4937ec21522bb12376cfa89942a7becbfe
font_01_sfnt_off00007827.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7827 10008 bytes
SHA-256: 330b39d2b3415d308c92e90fc38f8d76c7895c9a92afe8b87d061652a93f1e5c