Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c9e51b415a8736c…

MALICIOUS

PDF

83.4 KB Created: 2021-07-30 12:02:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f91f2d86946639681d8fbcd5e95d38c1 SHA-1: 48c79d28104a8362eb5298a9ac8ea0d7ab12c56d SHA-256: 6c9e51b415a8736ccfaf470200650e4877429811db61f6893feb1376a15fc1fc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs that form a link farm, with several pointing to compromised WordPress sites or disposable hosting. The document body is heavily obfuscated, but the presence of multiple external URIs and the 'link farm' heuristic strongly suggest a phishing or malware distribution attempt. No scripts were extracted, but the overall structure and URL patterns are indicative of a malicious intent to redirect users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://queure.ru/uplcv?utm_term=how+to+pay+unisa+online+application+fee PDF link annotation
    • http://irishheritagesociety.net/clients/7/7f/7f3653e4c5d791bf76f28d2bf9929747/File/72227200883.pdfIn PDF document text
    • http://navigator-nsk.ru/userfiles/file/numejefadaguteved.pdfIn PDF document text
    • https://rrr71.ru/upload_picture/vavanupexawufesiduzefup.pdfIn PDF document text
    • http://ccforum.kr/uploads/file/1622067303.pdfIn PDF document text
    • https://fultoys.com/userfiles/sujalegajabipedoritaw.pdfIn PDF document text
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/160a188f707801---70656478579.pdfIn PDF document text
    • https://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/3b394617abb21956a26ebb7d437ad615/11227077215.pdfIn PDF document text
    • http://innovatepc.com/userfiles/file/48675741659.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080d49aad13b---valamakigezor.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/16077339fe34fe---80386653058.pdfIn PDF document text
    • http://magendans.com/imagefiles/file/vaxexa.pdfIn PDF document text
    • https://doublehaircenter.com/upload/ckfinder/files/78392612981.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f99d6968383---81799666144.pdfIn PDF document text
    • http://brmhn.com/userfiles/file/20210702151329_c6k7gj.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/fe9d3d3d662a1ca8be536f3eabc09c00/kekizulozaluwatikom.pdfIn PDF document text
    • https://atiksigorta.com/files/93609045194.pdfIn PDF document text
    • http://turbotechnik24.de/userfiles/file/33957298394.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_off0000e1d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1D8 10664 bytes
SHA-256: 6d335d922bc83baca8907d6f4eff4490f78a61e45acab769ba7bce14af8538a2
font_01_sfnt_off0000fa79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA79 17012 bytes
SHA-256: 4806cf4eaea4dc167e312d968871098d5b6c1041e65e8097870b20aab2344ecf
font_02_sfnt_off000126b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1