Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8cd357565ba060b…

MALICIOUS

PDF

80.8 KB Created: 2021-06-29 02:15:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f4873d1712309c810b2609fab0523a98 SHA-1: c02ab03bd96294538e4b31592f5b7e1a59481a42 SHA-256: a8cd357565ba060b3255b1f5e86b40643b43310f3144a54ac88d5b92e6a512f3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of multiple compromised CMS upload links suggests an attempt to leverage legitimate-looking but compromised infrastructure for hosting malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://wills.sg/wp-content/plugins/super-forms/uploads/php/files/476225ec4abb76a6a139bcf57f828074/80227022487.pdf
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/1607e16fdc127d---4937569666.pdf
    • https://www.rydalmereprestige.com.au/wp-content/plugins/super-forms/uploads/php/files/u24vce1hb1ltr5hbmdi2uu04hk/35400163393.pdf
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/2df3720171b64f99576b7d20f3ba82cc/boxazozelebal.pdf
    • https://aartipalette.com/userfiles/file/98517259113.pdf
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a278ca9099---wutapitevikutuzujame.pdf
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/1f9e81b61bbd1c40363c1709c93982a8/wopimukupevuwexo.pdf
    • http://sparkpro.lv/content/file/pokafatolibekojino.pdf
    • http://gidaero.com/upload/fckeditor/file/jabexokowowozujanono.pdf
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/m6badc9vejf6p071jpghdk280o/maxunomuse.pdf
    • http://septumdent.com/img/userfiles/files/60558700027.pdf
    • http://24cvety.ru/upload/files/tinazobokefulawuwufepep.pdf
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/a1begargs7oin833rhev0ek4gc/9884405961.pdf
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ab458bc6b77---43935418727.pdf
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cf87f87cf3d---4542525674.pdf
    • http://aggengr.com/uploads/CMS/file/jidabajumibazodo.pdf
    • http://altaprecision.com/userfiles/file/98671388649.pdf
    • http://sns.hu/_user/file/vonuwuzudi.pdf
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/paafda8sd8vm7c7so3lfi3gft5/51335457208.pdf
    • https://247hvac.ca/fabulous1/uploads/files/6938549039.pdf
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/a8339db586135616cfa7958aeacebed3/57910231819.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=comprehensive+clinical+nephrology+6th+edition+pdf+download
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d396.bin
952d6ad0e96adcd8974416a53690f9c0f8dcd7e56ff3a89902b619941707afc9
pdf-font-stream PDF embedded font (sfnt) at offset 0xD396 11532 bytes
font_01_sfnt_off0000eea9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEA9 16792 bytes
font_02_sfnt_off000106bb.bin
4a817abcca63c135022a82c01f8089d3c13b405817c2a0ca9c1401fe16856bce
pdf-font-stream PDF embedded font (sfnt) at offset 0x106BB 18276 bytes