Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4ebc4dfca3fd8d9…

MALICIOUS

PDF

81.9 KB Created: 2021-04-24 18:48:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 9750ba78ed651f6e68ee49eb470ef09c SHA-1: 64d1f4c2810951881fc3ddd9c276c3bac9dbcb89 SHA-256: f4ebc4dfca3fd8d9eb807c7b27417a126ca20e0c8a1ca1880673e47bceb05c0d
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The presence of numerous external URIs, many hosted on seemingly legitimate domains but pointing to disposable PDF files, suggests a link farm or redirection mechanism. The document body, though heavily obfuscated, contains references to industrial automation terms, likely serving as a lure to disguise the malicious nature of the embedded links.

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://ambrose.edu/sites/default/files/webform/lajeriz.pdf In PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/loxigexaxezirizedud.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/povufukawonafano.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/26147793628.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/seliruni.pdfIn PDF document text
    • https://www.visitsavannah.com/sites/default/files/webform/fukixuliwidopisoduzurapi.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/topevonizudurazot.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/nolukaronedibikix.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/jokefogebefuzifuzew.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/19824824677.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/xikamiwaboloz.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.opentle.orgIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=allen+bradley+powerflex+40+fault+code+f005PDF link annotation
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/72323592377.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/83401752781.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/40347257249.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/42849177422.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
    • http://www.gnu.org/licenses/gpl.htmlIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f145.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF145 5716 bytes
SHA-256: 73665113faa19fcb5f84c5431024f4d8622d5cf706a58a5e21ae307c85420b12
font_01_sfnt_off000104e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104E4 6068 bytes
SHA-256: 7a02da73c5ff24218d04b188db7d31ceb9303d5dedd43b645f18a615a19d9b6a
font_02_sfnt_off00011495.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11495 10432 bytes
SHA-256: e1deac75fb31c31cc4e99425487cee9dccccebe86082b0cc1f132f6eb23ee7c2