Malicious PDF — malware analysis report

Static analysis result for SHA-256 e537ff661c583496…

MALICIOUS

PDF

84.8 KB Created: 2021-09-18 21:34:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b65750f29e19774c968c9440962e899f SHA-1: f035b17dac898beb671cdcfe02a44223d8cd0526 SHA-256: e537ff661c583496d5ac6f39ca5e1b5a63d50e5774dcc7084fd965cbbe25e503
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of embedded URLs, many pointing to disposable domains, suggesting a link farm or phishing lure. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to create a large number of links on potentially untrusted hosting. While no scripts were explicitly extracted, the nature of the embedded links and the detection as a trojan suggest it is designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://maschimaurizio.it/userfiles/files/14688972504.pdf In PDF document text
    • https://corpusbg.com/files/fck/file/78201633182.pdfIn PDF document text
    • http://chiangmaicharmingtravel.com/ckfinder/userfiles/files/pasevilopuruwowumuzu.pdfIn PDF document text
    • http://ubestsports.com/imager/files/20210912232131.pdfIn PDF document text
    • https://primer-spb.ru/files/files/40751304089.pdfIn PDF document text
    • http://buyyoutubesubscribers.com/ci/userfiles/files/44725977741.pdfIn PDF document text
    • http://billedbutikken.dk/articlefiles/file/netokiv.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16145378fe6e92---xisedososaposupilopan.pdfIn PDF document text
    • http://www.pavimentosyreformasferlu.es/ckfinder/userfiles/files/rizag.pdfIn PDF document text
    • https://swiz.eu/files/editor/97637807320.pdfIn PDF document text
    • https://megatekspb.ru/sites/default/files/uploads/tegemiwipeletokufizoz.pdfIn PDF document text
    • http://carlaschroyen.com/content_docs/84229173399.pdfIn PDF document text
    • https://andrejc.si/files/file/pokikominijugolefona.pdfIn PDF document text
    • https://nedimgame.com/calisma2/files/uploads/revejizo.pdfIn PDF document text
    • http://strandedtattoo.net/file/davuseril.pdfIn PDF document text
    • https://vicareyou.com/userfiles/file/46627675699.pdfIn PDF document text
    • http://missteenqueenuk.com/userfiles/file/16741942510.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109070851494715.pdfIn PDF document text
    • https://hashtag.school/userfiles/file/moledewebasusanewidifaviv.pdfIn PDF document text
    • http://24horasnoar.com.br/ckfinder/userfiles/files/semoxudofujonutenedok.pdfIn PDF document text
    • http://bdsps.org/slbdavbatala/userfiles/file/76644061540.pdfIn PDF document text
    • http://taispacedesign.com/upload/files/52139309108.pdfIn PDF document text
    • https://weishinclinic.com/uploads/files/202109030245342325.pdfIn PDF document text
    • https://trompis-tondschungel.de/userfiles/file/dipopotukorodafux.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=mxq+box+resetPDF 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_off0000e511.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE511 19200 bytes
SHA-256: a54a04a27ea83ff3244ad68f1024a26fdf12d1fc92eedeb535cfabf8d3d7565f
font_01_sfnt_off00011705.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11705 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012f1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F1C 10076 bytes
SHA-256: 5401654061496539b5f9000d3e8cd6d3c807b6c21936037644413853f57d7f1e