Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c146fe35c878004…

MALICIOUS

PDF

70.2 KB Created: 2021-09-19 03:26:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a932afa1f7bb3bbb6e65c242778d7468 SHA-1: 5654fc21db08f4d139969e49fe2a9b34c857a253 SHA-256: 0c146fe35c878004a70cdc82c4d86888adb269808d23e9a51ff9b204cca2e28f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it's a link farm on disposable hosting. The PDF contains numerous external URLs, suggesting a phishing or malware distribution lure. While no scripts were explicitly extracted, the PDF structure and numerous external links strongly imply an attempt to redirect the user to malicious content, likely involving JavaScript execution within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://synerhu.ru/uplcv?utm_term=cbr+reader+android PDF link annotation
    • https://ambient-interier.cz/files/files/zozunufewuram.pdfIn PDF document text
    • http://runo34.ru/attachments/file/29391321341.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/jerilafilogenus.pdfIn PDF document text
    • https://xn--72ca1bzcdf9cg5df4n5a8cei.com/userfiles/files/jixojobolip.pdfIn PDF document text
    • https://maxlinder.com/admin/assets/ckfinder/userfiles/files/36075330318.pdfIn PDF document text
    • http://artospace.com/pics/file/74850006996.pdfIn PDF document text
    • http://codemessaging.net/ckfinder/userfiles/files/9784365801.pdfIn PDF document text
    • http://skidubravy.sk/spravca/ckfinder/userfiles/files/pigodeju.pdfIn PDF document text
    • http://banhangcongnghe.com/upload/FCK/file/tolebe.pdfIn PDF document text
    • https://revive.fashion/upload/files/92261837215.pdfIn PDF document text
    • https://www.asoriofrio.org/ckfinder/userfiles/files/gugaket.pdfIn PDF document text
    • http://ibshop.gr/uploads/_uploads/files/10271449600.pdfIn PDF document text
    • https://jasz-pap.hu/UserFiles/file/difujomakujebiduje.pdfIn PDF document text
    • http://shinyoungvalve.com/userData/board/file/papugenobifota.pdfIn PDF document text
    • http://vaynhe.com/upload/files/sukil.pdfIn PDF document text
    • http://pwmtqatar.net/userfiles/file/zemumisutukubogerozekebe.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161467bbe7c681---74715123559.pdfIn PDF document text
    • http://ecosdaliberdade.com/ckfinder/userfiles/files/sipugavodavu.pdfIn PDF document text
    • http://votejoedestefano.com/editorData/file/pagesufakiwaguka.pdfIn PDF document text
    • http://suliaok.com/v15/Upload/file/202191195024503.pdfIn PDF document text
    • http://geasit.it/userfiles/files/34885950100.pdfIn PDF document text
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/161311fdf5b5eb---57970106304.pdfIn PDF document text
    • http://ags-sib.ru/ckfinder/userfiles/files/jararipixef.pdfIn PDF document text
    • http://youngthisyear.com/ckfinder/userfiles/files/pipufukufibususoxuki.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://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_off0000b240.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB240 16488 bytes
SHA-256: 876955e8ef185226383f1a855d3b9f11dd237909bda4ee9922329608469606a0
font_01_sfnt_off0000dc9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC9C 10100 bytes
SHA-256: 6c76350409583a8d48c847d1553c0c523dbcd7bcbf72b3247586fa1a177fd925
font_02_sfnt_off0000f331.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF331 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1