Malicious PDF — malware analysis report

Static analysis result for SHA-256 99c11063ef4a891d…

MALICIOUS

PDF

70.2 KB Created: 2021-10-03 04:50:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: fc00af3d6756c5c0a37095d06e48dd6f SHA-1: 82c4505f98cb9ce327f583163d1cb905bce0a61e SHA-256: 99c11063ef4a891d51299080567db6e34d645f5be3a7ea6f42d10e7749a649cc
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to external PDF files hosted on various domains, many of which appear to be disposable or used for link farming. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to distribute further malware or engage in phishing. While no scripts were directly extracted, the PDF structure and embedded links suggest a malicious document intended to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 http://srtcivilnorth.com/ckeditor_file/files/liwozigumajodasafosizaso.pdf In PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613c3c15a7ff5---lapojuzuxoli.pdfIn PDF document text
    • http://duquenne-moteurs.fr/webroot/upload/files/zubigalak.pdfIn PDF document text
    • https://koltoztetes-szallitas-lomtalanitas.com/ckfinder/userfiles/files/mabajotor.pdfIn PDF document text
    • http://www.ags-sib.ru/ckfinder/userfiles/files/manigatalinozelewupafop.pdfIn PDF document text
    • https://loyallcanada.com/editor_files/file/laxurexupajalinapa.pdfIn PDF document text
    • http://em-mould.com/ckfinder/userfiles/files/64132724133.pdfIn PDF document text
    • http://photo-ostrov.com/ckfinder/userfiles/files/27457973299.pdfIn PDF document text
    • http://zpkprzemysl.pl/ckfinder/userfiles/files/60199636382.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/493fcc52e340c346f7c3f9de703f6264/1977287519.pdfIn PDF document text
    • http://ooexperience.be/assets/Image/files/17895742929.pdfIn PDF document text
    • http://studiotravenzolo.it/userfiles/files/98486916367.pdfIn PDF document text
    • https://cualuoihoanmy.com/uploads/userfiles/file/kugumisilibibidujawo.pdfIn PDF document text
    • http://faradtvandor.hu/picture/userfiles/file/69981570842.pdfIn PDF document text
    • https://kenhquangcao.vn/uploads/files/99080914057.pdfIn PDF document text
    • https://www.leasing.net.in/ckfinder/userfiles/files/gifonipibuvibesu.pdfIn PDF document text
    • http://xn--80aafjbawrcdgsodbdciig4a5v.xn--p1ai/pict/file/seborefojetavibogukuvav.pdfIn PDF document text
    • https://tekstilkentrehber.com/upload/ckfinder/files/2879163703.pdfIn PDF document text
    • https://nyirfa.hu/uploads/files/gejor.pdfIn PDF document text
    • http://safeabortionnepal.com/userfiles/file/wemaferixuxuziba.pdfIn PDF document text
    • https://sangolongphuong.vn/longphuong/news/files/60317658797.pdfIn PDF document text
    • http://kooijobs.in/ckfinder/userfiles/files/momiba.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=list+the+general+properties+of+acids+and+basesPDF 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_off0000b0b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0B4 10996 bytes
SHA-256: 21acb134635c3eef0b4fee3b6a991cbbbc3ea5bb9e176ae539559b3903409e90
font_01_sfnt_off0000c9b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9B8 16112 bytes
SHA-256: 5dc549bb785aa68fcd63e02bda690f5df2c954fcd1851bfcd087ef99086d79bb
font_02_sfnt_off0000f2ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2AB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1