Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f67bc88efb34d09…

MALICIOUS

PDF

72.7 KB Created: 2021-04-12 21:41:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 1d3cc23d48db3deb92030ebb7784dfb3 SHA-1: 1c511f4218b24ca4226745e0dd063e086d5f671a SHA-256: 3f67bc88efb34d09b95263db986a3d1ce87fe5cd0f17c3d35215045a78ef2bec
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests it functions as a link farm, directing users to multiple domains, one of which is hosted on a disposable domain. The embedded URLs, despite some being marked benign, contribute to the overall suspicious nature of the document, likely serving as a lure for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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.
  • 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.uts.cw/sites/default/files/webform/89737617204.pdf In PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/3242210986.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/dufadurelabakugozuku.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/72917344941.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/27804174203.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/kivalin.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/mimixinaxeralowevowijut.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/zarogoluvesiriwameb.pdfIn PDF document text
    • https://www.termis.org/system/files/webform/88699151804.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=cultural+anthropology+emberPDF link annotation
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/9071701793.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/wosevojowavinojefe.pdfIn PDF document text
    • https://umatter.princeton.edu/system/files/webform/requests/tutoturabawukaxubudevodor.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/58023923203.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/54002061309.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d4d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4D9 5152 bytes
SHA-256: 23e76d0bb2ed54e9dd3c1be6e4bcd959aa7db2684ddf0b92cc05b1df005d5975
font_01_sfnt_off0000e639.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE639 9804 bytes
SHA-256: eb521d7883195dbbc29804525662914a4ca0002c5eda25d9d5da605c18222349
font_02_sfnt_off000107a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107A7 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176