Malicious PDF — malware analysis report

Static analysis result for SHA-256 135f63a8988f3a28…

MALICIOUS

PDF

168.7 KB Created: 2021-07-07 02:32:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e01f26f1b7d542a2b4d23ce4c0931d9f SHA-1: d7b00d422c7728876fb2b1287f8539f4ff0bb53c SHA-256: 135f63a8988f3a2869bf4b2e3428d9c2ec3f6b9aa2d523113b26d0a2cab1ab07
104 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to compromised WordPress sites, indicating a likely attempt to redirect users to malicious content. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple links on disposable or compromised hosting further supports this assessment. No scripts were extracted, and the document body was unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9939

Heuristics 6

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/12dcb6c0b212fafdf213dfbb2078dad6/50385289539.pdf
    • https://segurosjdd.com/wp-content/plugins/super-forms/uploads/php/files/cgcs887ji577ndggkb4ommval3/77589746263.pdf
    • https://www.lightingsolutionsal.com/wp-content/plugins/super-forms/uploads/php/files/ab2c0b0ee8af33a2fbb175d227da868c/1722073794.pdf
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cccaa624a3---bavopuforaloka.pdf
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/160c549506d509---dodisepipuxopekomanofe.pdf
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/786f7e84204ee3242d0e36380e48185e/23929012281.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160d2f5fb96c54---petovosudakitevajivufefi.pdf
    • http://delannahotel.com/user_img/file/sekututisegu.pdf
    • http://castudio.eu/userfiles/files/49193839614.pdf
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096266ea9bb9---84089334114.pdf
    • http://palyavalaszto.hu/teszt/upload/file/lajubi.pdf
    • https://sce.tw/uploads/files/60c1903f17b09.pdf
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/9un3ktp6o1ruoihk1btn9f6t3f/95325467328.pdf
    • http://gyorszol.hu/userfiles/file/zusuwekegumorusosazivu.pdf
    • https://alarrabnews.com/images/content/content/file/32450359897.pdf
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/r7soa64pcab7ciljiop8spktmb/janibozeterutejikulalire.pdf
    • https://mls.lighting/wp-content/plugins/super-forms/uploads/php/files/6861b5860f72a39ebbccb064f9830e39/botakumunadexujagutineso.pdf
    • http://mistral-paints.cz/userfiles/files/bekagokituru.pdf
    • https://wpsqld.com.au/wp-content/plugins/super-forms/uploads/php/files/45fe0c3a30de183184bf346cc477b9f6/96938335848.pdf
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160cfe64334ad3---fokesibilorezorofuzuv.pdf
    • http://buergerforum-tirol.at/file/65713367283.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=plasmodium+is+responsible+for+which+disease
    • 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_off0002325b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x2325B 16792 bytes
font_01_sfnt_off00024a72.bin
f0948ff23f5dbaf2139e2c96a0bde4c3d742cbeef2eadd026a5e4dfa56efbae3
pdf-font-stream PDF embedded font (sfnt) at offset 0x24A72 11116 bytes
font_02_sfnt_off000263f2.bin
82683b36ea557e345d094004f0cfb53612dafe9bc7446e3672d37fc5f9ddb60a
pdf-font-stream PDF embedded font (sfnt) at offset 0x263F2 18032 bytes