Malicious PDF — malware analysis report

Static analysis result for SHA-256 281b34e2dc95e731…

MALICIOUS

PDF

68.2 KB Created: 2020-11-10 22:05:30 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 4e49fcae06285437fe63dd60a561ecb8 SHA-1: 1e25a6ed8d148432205756370babe6209502c283 SHA-256: 281b34e2dc95e731a0f5970c8f85df2330a741c9e44e5603bc3fd26dc923e68c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external links, with one heuristic identifying a 'link farm' designed to distribute other PDF files. The presence of a 'download button' lure and the embedded URL further suggest an attempt to trick the user into downloading a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://trafffi.ru/123?keyword=key+root+master+english+apk
    • https://jipepusubame.weebly.com/uploads/1/3/4/0/134040653/loromawi.pdf
    • https://cdn-cms.f-static.net/uploads/4413575/normal_5f97c92d59dd7.pdf
    • https://cdn-cms.f-static.net/uploads/4367005/normal_5f88d560749f4.pdf
    • https://cdn-cms.f-static.net/uploads/4380867/normal_5f97825ef074b.pdf
    • https://cdn-cms.f-static.net/uploads/4443624/normal_5f9fdacd1e8fe.pdf
    • https://bikipejuroninoj.weebly.com/uploads/1/3/4/4/134448394/9425149.pdf
    • https://miragitoketulo.weebly.com/uploads/1/3/3/9/133997248/fobufaxor.pdf
    • https://kowevufewes.weebly.com/uploads/1/3/4/3/134388306/8644950.pdf
    • https://poriveba.weebly.com/uploads/1/3/4/3/134316211/f68fe76e148.pdf
    • https://kizekusoviwo.weebly.com/uploads/1/3/1/4/131453028/nivelemoxili.pdf
    • https://cdn-cms.f-static.net/uploads/4365584/normal_5f8c873f63bd5.pdf
    • https://cdn-cms.f-static.net/uploads/4424400/normal_5f9b0061657bc.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/jinabom/bexonajumabewofidub.pdf
    • https://s3.amazonaws.com/bidurudilidujug/nomizigafarigujar.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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ce41.bin
c75bae0777279018f4998bbb02e18ba8249d3f762eb74bf7578360b7245a9bb0
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE41 5368 bytes
font_01_sfnt_off0000e060.bin
c623161a4d86db4467bcbe5ab0f6e5d4c8dc3405dda9d489013f5466f1894b90
pdf-font-stream PDF embedded font (sfnt) at offset 0xE060 10360 bytes