Malicious PDF — malware analysis report

Static analysis result for SHA-256 f921e851212b334f…

MALICIOUS

PDF

74.6 KB Created: 2021-09-14 03:17:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 29ebc598d30270f1cd8673f85ef36749 SHA-1: 1de59a4257fb83d647d2d2ed76b6421597a8d043 SHA-256: f921e851212b334f8faf43444860bf917b7d0cc2bdccf448f3b5e00643e292ad
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. Heuristics indicate it functions as a link farm and a callback phishing lure, prompting users to call a number for a fabricated issue. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it is designed to deceive users into initiating contact, likely leading to further social engineering or fraud.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://elearning-chemistry.ro/userfiles/file/86285246387.pdf In PDF document text
    • http://denetimmusavirlik.com/userfiles/file/vesopubagibipozenotuj.pdfIn PDF document text
    • https://rosebankprimary.co.za/inc/ckfinder/userfiles/files/dewoxapujixapixat.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/161361ef699d11---71216470457.pdfIn PDF document text
    • https://spa-salon.ru/ckfinder/userfiles/files/puruv.pdfIn PDF document text
    • https://arrayamed.com/userfiles/file/jaxavazejarub.pdfIn PDF document text
    • http://rayocazar.com/images/elfinder-1.1/files/file/gefor.pdfIn PDF document text
    • http://medianet2000.net/amm_prod/image_news_popup/file/panoger.pdfIn PDF document text
    • http://dtyxbpzx.com/filespath/files/20210908165523.pdfIn PDF document text
    • http://skpizzasubs.com/uploads/files/xesasevepe.pdfIn PDF document text
    • http://dr-onesrl.com/userfiles/files/fevalokumarajefelofiromon.pdfIn PDF document text
    • http://apicn.net/upload/files/muwutewuv.pdfIn PDF document text
    • http://seidels-mineralienwelt.de/images/uploaded/file/tuwodamidilojure.pdfIn PDF document text
    • http://djapm.com/userfiles/file/88246725911.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e079b681f0---marivasi.pdfIn PDF document text
    • https://bc2000.order-pro.com/ckfinder/userfiles/files/28129614964.pdfIn PDF document text
    • https://hospvetcentral.pt/site/upload/file/pegitodonepaperenevetes.pdfIn PDF document text
    • https://traveletrust.com/basefile/traveletrustcom/files/35171805435.pdfIn PDF document text
    • http://ressourcengarten.de/azubi/userfiles/files/70335377527.pdfIn PDF document text
    • http://vigova.vn/Images_upload/files/jofopix.pdfIn PDF document text
    • http://sacoorhealth.pt/site/upload/file/wenarakusege.pdfIn PDF document text
    • http://harlit.com/ckfinder/userfiles/files/20210911_001400.pdfIn PDF document text
    • https://mysmartedu.com/uploadimages/files/samotipes.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=s21+ultra+sd+slotPDF link annotation
    • 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_off0000c076.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC076 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d888.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD888 17536 bytes
SHA-256: 507329b8b19f751cbb141daee688f88f54572a58cbfaab7a06da9bf7eab9ca6e
font_02_sfnt_off000105e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105E6 10260 bytes
SHA-256: 85812bc16a7e80a82aa3c406937602a9abf62530c49c6eefe53b11630a78683e