Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca55a254c64202dd…

MALICIOUS

PDF

75.1 KB Created: 2021-10-09 13:02:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 1b3f36914681bde1fea835415611d778 SHA-1: 5824129acfb5a69292e5e0e929ec6c64d838f824 SHA-256: ca55a254c64202ddb1629e1a65f95a0411fff408606bbe9497750c581744a2a8
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains embedded JavaScript and numerous external links, some pointing to compromised WordPress sites, suggesting it's used for phishing or to download further malicious content. The presence of embedded JavaScript indicates an attempt to execute code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://huarui-bio.com/upload/files/wivojaxovij.pdf In PDF document text
    • http://mcutech.net/files/3133100047.pdfIn PDF document text
    • http://hiace-yoshikawa.com/js/upload/files/zowezuro.pdfIn PDF document text
    • http://westpakusa.com/phpsites/vertical_living/uploads/file/niketowal.pdfIn PDF document text
    • https://www.auto-ecole-acm.com/ckfinder/userfiles/files/dovujadetirudujufolid.pdfIn PDF document text
    • http://spartapr.com/images/upload/file/90739429795.pdfIn PDF document text
    • http://olympusflights.com/files/files/juwigesozazimesiniz.pdfIn PDF document text
    • https://kocgrafikavukatwebsitesi.demowebsiteleri.com/upload/files/tofonusupexexebuzituxaz.pdfIn PDF document text
    • http://chingyi.tw/userfiles/files/65008615614.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16159df222f654---71298506520.pdfIn PDF document text
    • http://chinatriage.com/ckfinder/userfiles/files/gabuf.pdfIn PDF document text
    • http://dui-antidote.net/images/userfiles/file/zowurififajusudababusog.pdfIn PDF document text
    • http://resurrection-life.net/userfiles/files/finuw.pdfIn PDF document text
    • http://ikhmongol.mn/ckfinder/userfiles/files/renanidoruwufusakurur.pdfIn PDF document text
    • http://hosungtour.com/FileData/ckfinder/files/20210907_30392404E23A2DCF.pdfIn PDF document text
    • http://pointerboards.com/uploads/admin/files/refufafiz.pdfIn PDF document text
    • https://sbsoftware.ro/admin/userfiles/file/zavolif.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/161427e67142c1.pdfIn PDF document text
    • http://szymonadamczyk.pl/uploads/fck/file/43401614268.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ff9e671ada---27057349681.pdfIn PDF document text
    • https://theelementrama9.com/userfiles/files/zutisup.pdfIn PDF document text
    • http://rambud.pl/uploaded/file/15268519663.pdfIn PDF document text
    • http://waetsukai.jp/system/ckfinder/userfiles/files/51930976453.pdfIn PDF document text
    • http://ithalattagarantibelgesi.com/resimlerfiles/40453080295.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=how+do+i+get+rid+of+chest+fatPDF 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_off0000c39d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC39D 16584 bytes
SHA-256: fa434eb27216dfaa468061bc40c92478653717d53daea1a0ac4a19960bf0ee56
font_01_sfnt_off0000ee4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE4C 10684 bytes
SHA-256: 01a1756296bbe7ecb450b8f0b43bac5aca44cd9f16ddb2c3891c7ca3a3205d6f
font_02_sfnt_off000106c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106C1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1