Malicious PDF — malware analysis report

Static analysis result for SHA-256 859f3dd7c17f68b9…

MALICIOUS

PDF

79.4 KB Created: 2021-09-08 14:36:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 0b80f3707b04a00b11f461d95071650d SHA-1: c565a184ca38e1030533dbf577fe89061183dac6 SHA-256: 859f3dd7c17f68b98a1e0b5033834a78adf951d6b66651774a83680ad80d6553
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate it functions as a link farm, directing users to compromised WordPress uploads and other disposable hosting sites. The embedded URLs suggest a phishing or malware distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • 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.
  • 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://garglob.ru/uplcv?utm_term=separate+entity+concept+pdf PDF link annotation
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee69aca5d1---zobadila.pdfIn PDF document text
    • http://lse.hu/userfiles/file/nitojojebu.pdfIn PDF document text
    • https://taybaite.com/userfiles/file/lobixodakov.pdfIn PDF document text
    • http://eggtesting.com/admin/uploads/file/48717862181.pdfIn PDF document text
    • http://cbafjvn.com/uploads/userfiles/file/zomuzuxevup.pdfIn PDF document text
    • http://slabowidzacy.smprzemysl.pl/ckfinder/userfiles/files/48916884572.pdfIn PDF document text
    • http://gelikonline.ru/content/Files/boxusateresizixasa.pdfIn PDF document text
    • http://korea-seals.com/ckfinder/userfiles/files/67837368697.pdfIn PDF document text
    • http://giadinhmedia.com/uploads/files/fuwesilisojuwumigukire.pdfIn PDF document text
    • http://tecnoservizi.com/userfiles/files/82300458207.pdfIn PDF document text
    • https://strongpointmarketing.net/userfiles/file/83796314601.pdfIn PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/lawabizaxebegos.pdfIn PDF document text
    • http://pijntherapie.be/uploads/files/88068080349.pdfIn PDF document text
    • http://sentai.cc/data/file/20210908_022941_792.pdfIn PDF document text
    • http://revucue.com/ckfinder/userfiles/files/menopufoduzubitunefigeta.pdfIn PDF document text
    • https://beauty-full.ru/uploads/files/lawuked.pdfIn PDF document text
    • http://www.tm-africa.com/beta/public/uploads/cms_filescms_files/detuwotatiwupagavaxaz.pdfIn PDF document text
    • http://vinmexindia.com/uploads/1663473655.pdfIn PDF document text
    • http://www.petercar0937494634.com/upload/img/files/33238820498.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16134da9a0b395---83624789645.pdfIn PDF document text
    • http://toonesk.com/upload/xemevigodoji.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/qc0efjoono93ar03u7cnn3jpn0/butugemagapuvokowojela.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_off0000d324.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD324 17208 bytes
SHA-256: 8a9ae83b82198573f7ae81c52a663f528e84b0d35532f1455056b744d8ad0227
font_01_sfnt_off0000ff5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF5B 10588 bytes
SHA-256: cc710b424049c6a3eead0487b64a1f0c7c24393438df0d3d56f0abb6c5720935
font_02_sfnt_off000117ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117AE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1