Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef26b135a158aed4…

MALICIOUS

PDF

77.7 KB Created: 2021-09-07 20:36:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3e92df2b87e93e155f29ff0c30101181 SHA-1: 35fcb518c4fb9cc9f8c6ca007217f8f8a2a184fc SHA-256: ef26b135a158aed4a25023ed7fac0b8e7c140064a0cfa6c244720593afc21da0
156 Risk Score

Malware Insights

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

The PDF was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. It contains numerous external URIs, many pointing to compromised WordPress upload directories, suggesting an attempt to distribute malicious content or phish users. The document body is heavily obfuscated and contains no readable text, preventing further analysis of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9804

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://ceilford.org/wp-content/plugins/super-forms/uploads/php/files/afc705a5cf3bbe06f6b36eedb50d2f82/migegeworawurume.pdf In PDF document text
    • http://rajeshjshahani.com/clients/d/de/defaee86e9f1fedea086b53a5072ac2c/File/17022780057.pdfIn PDF document text
    • https://www.hotwaterfactory.com.au/wp-content/plugins/super-forms/uploads/php/files/1087dad88658f05edabf41b1a72368e2/sopuvizedotigivu.pdfIn PDF document text
    • https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b1bea8cd89---29564165588.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/llu6tb3e8ro9kjito046ssv16o/gipobika.pdfIn PDF document text
    • http://www.homefacelifters.com/wp-content/plugins/super-forms/uploads/php/files/fe686eb57256ac8a05ed7d543c166034/41001796797.pdfIn PDF document text
    • http://htcable.cn/d/files/ribam.pdfIn PDF document text
    • http://armanetti.com/images/kutev.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160785360d639a---bimaweviviluvipivimabud.pdfIn PDF document text
    • http://mofrantech.com/userfiles/file/damesogazovinop.pdfIn PDF document text
    • https://tavio.ru/files/file/19830229275.pdfIn PDF document text
    • http://esangsok.com/upfile/files/wovupuzofumexizotukili.pdfIn PDF document text
    • http://ecovn.vn/uploads/news_file/49292748724.pdfIn PDF document text
    • http://teleinwestor.pl/userfiles/file/72494879710.pdfIn PDF document text
    • https://www.bosingels.nl/ckfinder/userfiles/files/44652377036.pdfIn PDF document text
    • http://lobi.md/userfiles/file/gevezuvagiluwuxazavan.pdfIn PDF document text
    • https://semut73.com/contents//files/govokegokatijawesekede.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160878a6fd45a6---muzemudovonezuze.pdfIn PDF document text
    • http://zkpower.net/upload/files/86968220175.pdfIn PDF document text
    • http://freehajjandumrah.com/admin/admin/uploadfiles/file/zunawufo.pdfIn PDF document text
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/a38e2c5975f114ace4bd939252ebe494/datobusanefi.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1610654e33d12f---govemusudirejutivavuwadi.pdfIn PDF document text
    • https://travelstore.tn/userfiles/file/82192598568.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/a1tsj6vjq0jrss780gbfirqc11/79627665155.pdfIn PDF document text
    • http://cuanhomkinhtoanthang.com/media/file/kibinenebunawibari.pdfIn PDF document text
    • https://www.southdownscellars.co.uk/ckfinder/userfiles/files/1691524433.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=tinosorb+s+aqua+pdfPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bce4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCE4 1680 bytes
SHA-256: 6c08887b596ecb472c5a0482df8c2f828d83fc5b5d16111ed0caa1fced1b35dc
font_01_sfnt_off0000c4dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4DC 20564 bytes
SHA-256: 46c5ad467ab83070ed2a4781f657cbcdcd9c3defae29e5645e437202387f9df7
font_02_sfnt_off0000f8f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8F9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off00011110.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11110 10564 bytes
SHA-256: 26f5a625d8781cde2864fa8e2649e2cd227fa1fad46d5faf56e4afebb06f1984