Malicious PDF — malware analysis report

Static analysis result for SHA-256 c0c525ecf305aeb1…

MALICIOUS

PDF

79.3 KB Created: 2021-04-27 10:32:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: ac90ea8441bee935a88fade0f1ee13cd SHA-1: 8b4ba5d200daabc04c3128fa83d97667223da09f SHA-256: c0c525ecf305aeb1ea297186f234b89f817681407c60a93aa16634a61aaafd28
126 Risk Score

Malware Insights

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

The sample was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm on disposable hosting. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to malicious sites, likely for phishing or to download further payloads. The presence of multiple external URIs and the 'link farm' heuristic strongly indicate a malicious intent to distribute or redirect.

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/kepasibadugemefobovabo.pdf In PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/nojezajewi.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/64296936159.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/zuguxinukebezukul.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/45910982832.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/48862039041.pdfIn PDF document text
    • https://www.newburghgroup.com/sites/default/files/webform/resumes/talazeleravu.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/natogaj.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/fadubapep.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/xaduxiwipel.pdfIn PDF document text
    • https://natsihwa.org.au/sites/default/files/webform/degajakuko.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/nolukaronedibikix.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/kubuxodadiwozubak.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/40494538869.pdfIn PDF document text
    • https://www.afscme65.org/system/files/webform/tikat.pdfIn PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/kebadewanizokodijixupid.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/dofivefodazewinewes.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/loxigexaxezirizedud.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/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=zoom+g5n+guitar+floor+multi-effects+pedalPDF link annotation
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/vojevo.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_off0000e7b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7B9 5588 bytes
SHA-256: 33c7c82446568ac85cf05c92e63a5fea0134ac741bce4a7932e29c8ebd3ac624
font_01_sfnt_off0000faae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAAE 6068 bytes
SHA-256: 7a02da73c5ff24218d04b188db7d31ceb9303d5dedd43b645f18a615a19d9b6a
font_02_sfnt_off00010a5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A5F 10856 bytes
SHA-256: b1cb31629b88f7fdd18005586fb86627979317659d40e8d3c9657139bcd505eb