Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c24d674833e1464…

MALICIOUS

PDF

131.2 KB Created: 2021-03-24 23:47:53 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 03b862923b6a22b2e468846de0de650e SHA-1: 7d0f6b2ddc0a8d79a0ba064bb19cb40e4a21d817 SHA-256: 6c24d674833e14645c8df4a97e479299dc3812c780b3a1a234b0f39bfacff698
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or redirection scheme. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • 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.
  • 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://dafemum.ru/123?utm_term=irrational+synonym+informal
    • https://talunijepi.weebly.com/uploads/1/3/4/5/134599753/vulofij.pdf
    • https://cdn-cms.f-static.net/uploads/4393361/normal_6015d6625c80a.pdf
    • https://nagozexifetuli.weebly.com/uploads/1/3/4/3/134340384/puzadisewawe-vorew-fubofudo-xosexezopefit.pdf
    • https://cdn-cms.f-static.net/uploads/4460983/normal_6037b8fb6f258.pdf
    • http://vekogevev.22web.org/kuwaxa.pdf
    • https://static.s123-cdn-static.com/uploads/4390660/normal_5feb49b8c48b0.pdf
    • http://dojisef.iblogger.org/gepebib.pdf
    • https://static.s123-cdn-static.com/uploads/4393759/normal_5fde9a03e39be.pdf
    • https://bivolureru.weebly.com/uploads/1/3/4/5/134583024/budaf-dakepefaji-lozore-pegufuwavinel.pdf
    • https://vizexetu.weebly.com/uploads/1/3/4/8/134864552/1207933.pdf
    • http://www.opentle.org
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://fedorahosted.org/lohit
    • https://uploads.strikinglycdn.com/files/aa53c125-ab6e-49b6-a07a-2c65e124dbe2/human_body_systems_and_their_functions.pdf
    • http://xugomoxuniwemo.rf.gd/mepubexerilugiziz.pdf
    • http://xujamaxopubisa.rf.gd/wosija.pdf
    • http://voperafabekom.epizy.com/nixon_the_sentry_chrono_leather.pdf
    • http://lonelogu.epizy.com/zixediluwajelajakagonoz.pdf
    • https://ae9cd3fc-a2ed-4114-aa96-dd53a7e96ab4.filesusr.com/ugd/22cbe6_6045c11669764727977f79e249c90f31.pdf?index=true
    • https://47a25507-5c4f-4e73-9b7c-0c49514c8174.filesusr.com/ugd/e00bd3_bdaf970bdf6b4339aef6024c4d4eec29.pdf?index=true
    • https://8717ace1-8174-44a1-9f98-e7cbf9e9ed94.filesusr.com/ugd/14e3be_e977285ce81c4effb392188aba984ce3.pdf?index=true
    • https://uploads.strikinglycdn.com/files/17be9305-bc27-4c0b-8020-6b76d9d18912/jokavesusexunotoluxe.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://www.gnu.org/licenses/gpl.html
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License
    • http://scripts.sil.org/OFL

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00016539.bin
d6d38be4b0412e1b8a30e283099825e579be816c163a1139059edc65fec5a431
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x16539 8572 bytes
stream_006_off0001bfda.bin
e6f51b2d06327c9e9d2fea300512431b4d89b39c75b50869884437d28766c84e
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x1BFDA 24308 bytes
font_00_sfnt_off00012a48.bin
5f3dd12ff6fa6821b68bba875f9c7894a03c2585b7c55e781d5763deecfea6b2
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A48 12688 bytes
font_01_sfnt_off0001547c.bin
077a3c794a2a71414173f372d06fb28477329e0e329a75a27592c3b39d058bd4
pdf-font-stream PDF embedded font (sfnt) at offset 0x1547C 4952 bytes
font_03_sfnt_off00017d5d.bin
62a75914112fb62f834ef9701e8909bb147982c667a1dbc84740fccb2b906994
pdf-font-stream PDF embedded font (sfnt) at offset 0x17D5D 24628 bytes
font_05_sfnt_off0001eb47.bin
a7bad97b3fcdb9777ae7df7970860d420b4b26175b4632641c46fb745a7a47e4
pdf-font-stream PDF embedded font (sfnt) at offset 0x1EB47 4608 bytes