Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7670611e620a3b4…

MALICIOUS

PDF

76.8 KB Created: 2021-09-02 16:23:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 9a9a0c8ab0a98a19b7a1031cf60f32e3 SHA-1: 282a9ce39a52ffc2dc8cecb628e5b3dacc2d84da SHA-256: b7670611e620a3b4912313bf1c7791534f3686b898e0e29eb935557283e81491
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised WordPress upload storage and disposable hosting, with multiple external URIs. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its true purpose, which is likely to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://drafthe.ru/uplcv?utm_term=international+phonetics+alphabet+chart+pdf PDF link annotation
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16079065852562---42715173840.pdfIn PDF document text
    • http://al-bandak.com/userfiles/file/xelazebafe.pdfIn PDF document text
    • https://orldoc.ch/wp-content/plugins/super-forms/uploads/php/files/g81tsl5t2ojupm40e3ur1ateb1/rajoperufigavo.pdfIn PDF document text
    • https://grandhotelbulgaria.com/userfiles/file/maverunajuzuve.pdfIn PDF document text
    • http://loaamtran.vn/files/usersfiles/files/kadekeregevogibupisi.pdfIn PDF document text
    • http://purofirstli.net/userfiles/file/68686544315.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee7df631787---94913914568.pdfIn PDF document text
    • http://www.sandzthabapanel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160f6372bb364f---51848788317.pdfIn PDF document text
    • http://worldsocialistpartyindia.org/ckfinder/userfiles/files/59686586510.pdfIn PDF document text
    • https://icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/bobiraroronuxiwolemamifuj.pdfIn PDF document text
    • https://atvatextile.com/upload/ckfinder/files/pilawikutebixiri.pdfIn PDF document text
    • http://gorisum.net/fckeditor/upload_file/file/13992402664.pdfIn PDF document text
    • https://radmangroup-ye.com/rgfiles/file/lojurelilijavako.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084b4379d854---ketit.pdfIn PDF document text
    • https://djennebeads.com/nbloom/fckuploads/file/mopolofulonuga.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/lunoxavipesusimoduki.pdfIn PDF document text
    • https://implant-drill.com/userfiles/file/pamar.pdfIn PDF document text
    • https://mobiligennari.com/userfiles/file/zotanijamerifaximaludoj.pdfIn PDF document text
    • http://learningkey.org/userfiles/79305665203.pdfIn PDF document text
    • http://amadpich.com/userfiles/file/vepigatuxififebufo.pdfIn PDF document text
    • http://korea-labels.com/ckfinder/userfiles/files/71938902836.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/95559818741.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16125b804450d1---7946779979.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b9e9430730d---jefipikumejinujeronotux.pdfIn PDF document text
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/ms6h433ouvj0fdom923tc8ktff/sukurazizibej.pdfIn PDF document text
    • https://kildevangen.dk/files/tunodivuxunawo.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_off0000c506.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC506 18340 bytes
SHA-256: f0be73188d5509ac89b7b946c705ca9a958ef4b546d6eef4baf88db16de271e4
font_01_sfnt_off0000f4ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4BA 10808 bytes
SHA-256: f54c22b497c0336c76a69c38329174449e3357092fb5c75f3e7752b9e6604db2
font_02_sfnt_off00010d49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D49 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1