Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9ccb158bcaa3972…

MALICIOUS

PDF

64.4 KB Created: 2021-04-25 04:46:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 559b2fa7ed62c0640abd33f5eed0ae8f SHA-1: de7859a846dcb09bd1fb10b3b086a0503a043348 SHA-256: a9ccb158bcaa3972df900e75e4e251a5c741465e0b6339e7bcdec7e3372936ef
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm. The document body contains garbled text, suggesting it is not intended for direct user consumption but rather to host links. The presence of numerous embedded URLs pointing to various domains, many of which appear to be legitimate sites repurposed for hosting, supports the link farm hypothesis. While no scripts were explicitly extracted, the PDF structure and heuristic findings suggest potential for embedded malicious JavaScript or other exploits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://www.natsihwa.org.au/sites/default/files/webform/doxuwekuwazomiloxeri.pdf In PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/42535902170.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/41164207556.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/33269367294.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/238550972.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/69774832497.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/9555400870.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/pexutagizoniged.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/durigoxilakomisi.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/40110328039.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/26511902049.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/nolukaronedibikix.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=berklee+music+theory+book+1+audioPDF link annotation
    • https://lib.asu.edu/system/files/webform/nexeginexepor.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/65601020807.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/fumegefexuwonadijot.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c0f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0F7 5588 bytes
SHA-256: 7717d77ffcae9f3feef591a311b3041a4d7b4ed0c4eba27a3baf30f95ab42b0a
font_01_sfnt_off0000d3d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3D7 9732 bytes
SHA-256: 92ee4b7f09bc86a417e22c0ef6b5ae31ef13dc29c851b89a199f3bb729c3ac9d

Open this report in the interactive analyzer, or submit your own file for analysis.