Malicious PDF — malware analysis report

Static analysis result for SHA-256 37f727a667904cd3…

MALICIOUS

PDF

82.1 KB Created: 2021-09-11 07:48:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 55ad26ec3e84f2a1fe1b961dc529c229 SHA-1: abf2329eb7b5c65eb0a79693b10fd34dcfb3bd94 SHA-256: 37f727a667904cd39f6a9aa0378bfb74f74ede2aa5390c73906700f88d216d6c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a high number of embedded links, many pointing to disposable domains, which is characteristic of phishing or malware distribution campaigns. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and appears to be malformed, likely due to the wkhtmltopdf generation process, but the presence of numerous links to external PDF files suggests a lure to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://sluganarodu.org/userfiles/files/mokexadavovadidamen.pdf In PDF document text
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/gavulex.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/161354ef8df186---14963146064.pdfIn PDF document text
    • http://bugskin.org/userfiles/file/45557998390.pdfIn PDF document text
    • http://debten.net/UserFiles/File/1534421652.pdfIn PDF document text
    • http://www.sana-anong.com/ckeditor/ckfinder/userfiles2/files/20587637328.pdfIn PDF document text
    • http://tradeweb.es/userfiles/file/lafafuluguberu.pdfIn PDF document text
    • https://tjpapigroup3.com/contents/files/44452705720.pdfIn PDF document text
    • http://dtpokebar.com/uploads/files/gamixamuzonekaroxazavuwut.pdfIn PDF document text
    • http://sxnqx.org/upload/file/Fl202109070655549015.pdfIn PDF document text
    • https://pioneerlift.com/upfiles/editor/files/wavezedofajesobo.pdfIn PDF document text
    • http://caerulumpharma.com/upload/files/temurexu.pdfIn PDF document text
    • http://astmasme.com/userData/board/file/69618060819.pdfIn PDF document text
    • http://www.gpkoaee.ru/ckfinder/userfiles/files/jisiwuzaxewagofakokeje.pdfIn PDF document text
    • https://kitapkaplama.com/upload/ckfinder/files/xilewejakile.pdfIn PDF document text
    • https://waxparadise.pl/userfiles/file/16304389199.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130c5228bbc7---795441624.pdfIn PDF document text
    • http://comlark.ru/userfiles/files/tupef.pdfIn PDF document text
    • http://orosweb.hu/ckfinder/userfiles/files/78515771528.pdfIn PDF document text
    • http://geodavidepini.it/userfiles/files/gowosozezokibodewup.pdfIn PDF document text
    • https://chrmglobal.com/userfiles/file/2633950951.pdfIn PDF document text
    • http://skncn.com/u/files/22107428321.pdfIn PDF document text
    • http://www.valathors.com/ckfinder/userfiles/files/jekosez.pdfIn PDF document text
    • https://soi.icami.mx/ckfinder/userfiles/files/85941679755.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=how+to+save+an+indesign+spread+as+a+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://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_off0000da39.bin
739694a61795cf733cecdb5225d69792aa049b509fe438edfd73787baf5c7d69
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA39 18328 bytes
font_01_sfnt_off000109b1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x109B1 16792 bytes
font_02_sfnt_off000121c8.bin
103a9aae69c1b8a7c097382e41580896c9eea2222b7b2689da3899998b1d3c34
pdf-font-stream PDF embedded font (sfnt) at offset 0x121C8 10768 bytes