Malicious PDF — malware analysis report

Static analysis result for SHA-256 5decdfa90c0c6260…

MALICIOUS

PDF

95.9 KB Created: 2021-04-07 08:15:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 7f416dac32d094cf83f4880fc4f0e39e SHA-1: dc3068a1bb7d9e7baca1ad69d51c26edd300ba85 SHA-256: 5decdfa90c0c6260abf1b7480b9533442be0b0bf96d8ee23bc8d7f4e85ae1b38
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many pointing to disposable hosting services, and is flagged by ML classifiers and ClamAV as malicious. The embedded URLs suggest a link farm designed to redirect users to potentially malicious content, masquerading as academic material. No scripts were extracted, but the overall structure and URL patterns indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 6

  • 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 contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://botokaw.ru/wix?keyword=academic+chemistry+final+exam+review+answer+key PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4416502/normal_604e166eb2454.pdfIn PDF document text
    • http://jivopifavu.22web.org/97093396519.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378153/normal_60144dc4d473f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495985/normal_6063f7db48687.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4410986/normal_6002d74f7b030.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420745/normal_603e48b6396c5.pdfIn PDF document text
    • http://magarunu.iblogger.org/encephalite_nmda.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://67258aaf-84c5-4a88-bfd2-1aa7ddb6c27a.filesusr.com/ugd/850f07_a7ac0a0f130d4c1381833f721e725bbc.pdf?index=trueIn PDF document text
    • http://pisubuxave.rf.gd/43032805742.pdfIn PDF document text
    • https://67258aaf-84c5-4a88-bfd2-1aa7ddb6c27a.filesusr.com/ugd/850f07_02e56ca4d97a433ca7c863d54c42bf4c.pdf?index=trueIn PDF document text
    • https://40e214c1-1950-44e8-a195-e2c6eeb23253.filesusr.com/ugd/a517f4_390fc81d9aa547b3b0ccb928daa45270.pdf?index=trueIn PDF document text
    • http://noxikemudenuma.epizy.com/guidelines_for_pneumatic_tube_delivery_systems.pdfIn PDF document text
    • http://gizamir.epizy.com/que_personaje_de_cazadores_de_sombras_eres.pdfIn PDF document text
    • http://lutubipejor.rf.gd/65383760155.pdfIn PDF document text
    • https://84d5b3ab-51dd-4312-87b7-51df18fb3b26.filesusr.com/ugd/9ea9b6_12cfdd9940ac4e06b6219a4a80ffd63b.pdf?index=trueIn PDF document text
    • http://puwagof.rf.gd/tesivakafup.pdfIn PDF document text
    • https://23751d96-d7b3-42ca-b8ca-e459b671ea95.filesusr.com/ugd/7de994_2df3d42d69174b799976399dfc7f604c.pdf?index=trueIn PDF document text
    • https://6090ae5c-070c-4b50-bfd2-11a66789f099.filesusr.com/ugd/83cce3_db73883415864bc1b5c13c820068a642.pdf?index=trueIn PDF document text
    • https://229c3593-bb94-4e5d-9b9f-ca3747df48ef.filesusr.com/ugd/145364_3e4b06537a684a4ca1f5736c1ca184ac.pdf?index=trueIn PDF document text
    • https://1a2149e7-ca7f-4e7c-a584-0e483de6f3af.filesusr.com/ugd/9219f8_4fe3bbdf086f4a3db3da27ea6c2cb016.pdf?index=trueIn PDF document text
    • http://jejivosijej.rf.gd/fopolikowotifojonexijime.pdfIn PDF document text
    • https://cb6d8354-940b-4e05-9f1d-0150973ab277.filesusr.com/ugd/882da0_844d68ef285541098d1eb14d4c66445d.pdf?index=trueIn PDF document text
    • https://9a4b5e96-23fe-4021-9525-787506808755.filesusr.com/ugd/b3318b_d9855ea851d54878b094ee2a37d348c4.pdf?index=trueIn PDF document text
    • http://gefetela.epizy.com/jquery_api_documentation.pdfIn PDF document text
    • https://f45985d3-969e-4a4b-a16b-f92b7c881388.filesusr.com/ugd/20da2d_29eec2c31a1f411a838fb89d2e66f272.pdf?index=trueIn PDF document text
    • https://ddf64d59-5240-4154-9987-17dfc28e22c7.filesusr.com/ugd/cec570_eaecc812970140a3a60e834e09b866e5.pdf?index=trueIn 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://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_off00011bb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BB8 5636 bytes
SHA-256: 44e193de1354d73709a2c79e9e94ca23fd4f8a6e1c355a7c04066345bf9d102c
font_01_sfnt_off00012ed6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ED6 12828 bytes
SHA-256: c63a50364bc97c55256b4ee5b98cf01aa23745dc5c4c0b360eb90f159f54e2ab
font_02_sfnt_off00015a7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15A7A 16204 bytes
SHA-256: e93acd332f5893643511f4cefd38969ad5c744ad1b08842a788b6be7d277dd15