Malicious PDF — malware analysis report

Static analysis result for SHA-256 fd44d4ce9d0cd2c6…

MALICIOUS

PDF

74.6 KB Created: 2021-09-18 13:15:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a87864b33ff3a4f8938f3e30988230ae SHA-1: 03a257ebd93f4ac1da67ae18e55eb472c02f134a SHA-256: fd44d4ce9d0cd2c6f73fb20cc7971592844c9d172fad128568ac0dd6034d9b38
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features a large number of external links, many pointing to compromised WordPress upload directories or disposable hosting, indicating a phishing or malware distribution attempt. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://karlsbach.de/userfiles/files/72735166754.pdf In PDF document text
    • https://aronabritcan.com/userfiles/file/meneviza.pdfIn PDF document text
    • http://fujieshubao.com/zk/UploadFile/file/2021091216021473499.pdfIn PDF document text
    • http://aygroupmuh.com/image/files/gexadedonetawezife.pdfIn PDF document text
    • https://lrsdev.com/userfiles/file/85637661959.pdfIn PDF document text
    • http://www.velkoobchod-man.eu/ckfinder/userfiles/files/9641257630.pdfIn PDF document text
    • https://accounting789.com/ThImg/file/33176911231.pdfIn PDF document text
    • http://hyundai-dongdo.vn/images/files/2856915121.pdfIn PDF document text
    • http://netisiletisim.com/guvennet/resimlerfiles/kinepi.pdfIn PDF document text
    • http://sartor.ru/upload/files/33319106360.pdfIn PDF document text
    • https://egokituz.eus/files/galeria/files/80854784030.pdfIn PDF document text
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/b0d86bf62a6959cf26adcd32460387fe/78726148386.pdfIn PDF document text
    • https://chachachat.info/js/ckfinder/userfiles/files/zusaged.pdfIn PDF document text
    • http://euskararenginkana.eus/files/galeria/files/netefusif.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/16135bc07a7351---tojofuxamabolodageri.pdfIn PDF document text
    • https://ntc-container.com/upload/files/11155605392.pdfIn PDF document text
    • https://edenestates.com/ckfinder/userfiles/files/76507831616.pdfIn PDF document text
    • http://llux.vn/uploads/files/9734572581.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf5482cc4e---gamevujuwaluvubiw.pdfIn PDF document text
    • https://specialgarden.ro/userfiles/file/wazutewanazoga.pdfIn PDF document text
    • http://derkwoo.com/upload/editor/files/37722436966.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=into+the+spider+verse+streamPDF 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_off0000bfa1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFA1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d7b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7B3 17416 bytes
SHA-256: 4f4609370d753b4e3021886f4d4ca257c0dc19e640d3862bf52757401cc5fc6c
font_02_sfnt_off0001051b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1051B 10628 bytes
SHA-256: 7ca4a8544e519782adbbd11357723e287f69f92490a8ec4ac843700f40695c71