Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1c73aa157c53878…

MALICIOUS

PDF

68.5 KB Created: 2021-09-24 15:53:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 82ae7267d02cda6797c0c9ffa77c4c43 SHA-1: 35141b713bb3ba754344abea0b0c3fe91fbd4b60 SHA-256: f1c73aa157c53878e97f06106a98fc4991c5f56b646f9bf294195b9faed79c0f
86 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was identified as a malicious screenshot lure, designed to trick users into clicking embedded links. The document body is heavily obfuscated and contains no readable text, but the heuristics indicate it is a link farm hosted on disposable domains. The ML classifier strongly supports the malicious verdict.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

Heuristics 5

  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 68 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://eternoohydro.com/d/files/rexiwujuselexep.pdf In PDF document text
    • https://phoenixturkey.com/upload/ckfinder/files/53147942496.pdfIn PDF document text
    • http://walosports.cl/userfiles/file/68395815274.pdfIn PDF document text
    • http://synergienetwork.net/userfiles/file/4186212789.pdfIn PDF document text
    • http://eptesteplelek.com/uploads/file/37871646769.pdfIn PDF document text
    • https://estudiowebcolombia.com/ckfinder/userfiles/files/9998303612.pdfIn PDF document text
    • https://3rproject.eu/ckfinder/userfiles/files/liminiwaxegawanijofirati.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/161326ea5aa89c---muvumufa.pdfIn PDF document text
    • http://gpmpoolandspa.com/ckfinder/userfiles/files/jufesegugoronoref.pdfIn PDF document text
    • http://cieplej.pl/imgturysta/file/wenuwewejufida.pdfIn PDF document text
    • https://classconnbio.com/img-jacson/files/sufunilu.pdfIn PDF document text
    • http://gospel-pour-100-voix.com/fichiers/newsletter/file/29629168128.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147dc41021e1---5982474390.pdfIn PDF document text
    • http://highendschmiede.de/highendfiles/file/getixutidupewux.pdfIn PDF document text
    • http://zssadkowice.pl/pliki/37120306146.pdfIn PDF document text
    • http://bangladeshceramicsociety.com/uploads/editor/files/dukeji.pdfIn PDF document text
    • http://ceramicaartisticamarsalese.it/userfiles/files/xapuwowaguvug.pdfIn PDF document text
    • http://zhfangyuan.com/uploadfiles/files/11415279077.pdfIn PDF document text
    • http://parfumerieindex.nl/images/uploads/94500311636.pdfIn PDF document text
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/61451127461467141c3b79.pdfIn PDF document text
    • http://allier.proximeo.com/ckfinder/userfiles/files/vulabejomamumedafej.pdfIn PDF document text
    • http://tnshoppingbag.com/upfiles/file/xetor.pdfIn PDF document text
    • http://cmuniontravel.com/userfiles/files/bukogufikavabob.pdfIn PDF document text
    • http://khocabien.com/uploads/files/74358541218.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=view+profile+private+instagramPDF 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_off0000ae12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE12 14312 bytes
SHA-256: c1dcffbe2ca654c60f37a725ade58576b2da021c579fc41b7ab6783c6d8d5953
font_01_sfnt_off0000d17c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD17C 10824 bytes
SHA-256: 4e48403b4994ed85bbb4ba6d4e42b30a2761c5d11b17694731fb7bd867856329
font_02_sfnt_off0000ea83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA83 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1