Malicious PDF — malware analysis report

Static analysis result for SHA-256 b989391adf2fb3f4…

MALICIOUS

PDF

71.3 KB Created: 2021-09-19 01:46:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: c22e276fc2c19ca6b84699fe5f33181b SHA-1: 084e2a90475fbf64eb43d10f5520b5e0d050038b SHA-256: b989391adf2fb3f44868c57ddd32ecca78dbf126736c8060a682babb8d76d070
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to disposable domains, and is flagged as a link farm. The 'SE_CALLBACK_LURE' heuristic suggests a phishing or tech-support scam pretext, aiming to trick users into visiting these sites. While no scripts were explicitly extracted, the nature of the embedded URLs and the link farm heuristic strongly suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://krisoc.ru/uplcv?utm_term=how+write+envelope+address PDF link annotation
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613568e7f0727---48741499310.pdfIn PDF document text
    • http://abwlargo.com/uploads/files/dekapebemebowelowe.pdfIn PDF document text
    • http://vansuloi.com/uploads/userfiles/file/zewok.pdfIn PDF document text
    • http://avvocatogiuliani.it/userfiles/files/nuvenevukuvigigeteroxus.pdfIn PDF document text
    • http://digitalpolicycouncil.org/imagenes/file/xaposavapij.pdfIn PDF document text
    • http://abwferrellpkwy.com/uploads/files/pukogopofosaf.pdfIn PDF document text
    • http://nieruchomosci-swidnica.pl/userfiles/file/15002378124.pdfIn PDF document text
    • https://santa.sg/images/users/00000000/files/rofuraladiwavug.pdfIn PDF document text
    • https://apra.pl/files/file/14799826160.pdfIn PDF document text
    • https://walnutcreekguide.com/wysiwygfiles/file/duxerozinebowomujevo.pdfIn PDF document text
    • http://waxiangyuan.com/upload_fck/file/2021-9-4/20210904203450169097.pdfIn PDF document text
    • http://tomgiongvip.com/uploads/files/file/91337857995.pdfIn PDF document text
    • http://ctmmaximoravenna.com/ckfinder/userfiles/files/208164610.pdfIn PDF document text
    • http://chizclean.ru/files/fck/file/zegivinufuxila.pdfIn PDF document text
    • https://htchninc.com/d/files/75503030061.pdfIn PDF document text
    • http://retrolondontees.com/userfiles/file/97237998160.pdfIn PDF document text
    • https://kontiko.com/ktkweb3/images/upload/files/litegiso.pdfIn PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/790c52f935af571659d13ddb84d7068d/6806959772.pdfIn PDF document text
    • http://kantoromega.pl/userfiles/file/xowobirepo.pdfIn PDF document text
    • http://xn----9sbbnbtte4cyg.xn--p1ai/ckfinder/userfiles/files/bawetazo.pdfIn PDF document text
    • https://ksuskalology.com/images/file/buwoke.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_off0000b5c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5C5 16360 bytes
SHA-256: 1c4b5987a0e6e5c0df8d90095694f42d3b6c4275111ff1aa5313a198c30272b0
font_01_sfnt_off0000e016.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE016 10528 bytes
SHA-256: f85492450fc01857b0ce8e88320f5b791529421d2288ea8df90b419b961fd8e5
font_02_sfnt_off0000f833.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF833 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1