Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a28706b8d4cf51f…

MALICIOUS

PDF

91.8 KB Created: 2021-07-02 18:27:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1440376c72aa63b3a8ebab555e750d4e SHA-1: 2715d21dee3689b687c9bb958512ba071ccc2a56 SHA-256: 9a28706b8d4cf51f119386740ed593680b8fbc236ce9f9e5982cb45c07d67a33
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to redirect users to potentially harmful content. The presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 http://www.publicitymailing.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1607dfed8d1f34---79251587096.pdf
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ab25f8dba60---vaxarijozogoxuba.pdf
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cb57e36ab6f---90114995136.pdf
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/9b225163dffc2505b547adb747ebdcf0/55029858022.pdf
    • http://onlinemidias.com/ckfinder/userfiles/files/putud.pdf
    • http://portalpr-b2b.es/img/user///file/_0359716001624367810.pdf
    • https://engineeredrepinc.com/wp-content/plugins/super-forms/uploads/php/files/af0f6f38d741239c7265608c4acd4625/fizavenidebetetefa.pdf
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/70b574f8468634f605cbf27a66fa02a6/dususujulof.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bb8028a2087---33326694230.pdf
    • http://sage-chem.com/image/files/20210614_042950.pdf
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160737905b7e8c---bepowepare.pdf
    • https://alexandrapanayotou.com/web/images/static/file/sawowira.pdf
    • https://pmeds.us/userfiles/file/61511874501.pdf
    • http://sequoia60.com/clients/875776/File/wukodobekom.pdf
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cad6a589c9f---lufopegokuxaperegevev.pdf
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/160809f039b379---51970502234.pdf
    • http://ahkjt.com/upfile/file/40020755863.pdf
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c841910a7a---pesek.pdf
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608907459d16a---kawisezawunijizupuge.pdf
    • http://alexlunacoach.com/img/editor/file/wonikerabajevedoweze.pdf
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b9938cf9fa---76819102568.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=find+the+area+of+the+shaded+region+in+figure+if+abcd+is+a+square+of+side+7cm
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eadd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEADD 16792 bytes
font_01_sfnt_off000102ef.bin
09fbc412358ea1bf1b851d38a7c9655d8ecf6adc6fc84ed82621116bb6b89974
pdf-font-stream PDF embedded font (sfnt) at offset 0x102EF 17492 bytes
font_02_sfnt_off00013180.bin
1bb543891201b86cb218c82ce0c1e431878b85d3145a79f40ea94bf38162e691
pdf-font-stream PDF embedded font (sfnt) at offset 0x13180 16144 bytes
font_03_sfnt_off000146dd.bin
e944ab8935b1da643064fa0a63e1ed7e61108cf6a8a512067e9ad170b6cc89d5
pdf-font-stream PDF embedded font (sfnt) at offset 0x146DD 11288 bytes