Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c8bd1c04c19f3f0…

MALICIOUS

PDF

89.8 KB Created: 2021-09-24 03:53:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5f457189451f92876fa7a54183f5a9e4 SHA-1: 3cc67d88a91478df1ff833aa29e3929cc63e80a4 SHA-256: 1c8bd1c04c19f3f081f11f7b290972e5e60e8051853d4339bc9b968bab184a25
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous external URIs and points to compromised CMS upload storage, suggesting it's designed to redirect users to potentially harmful content. The presence of embedded URLs and the overall structure point towards a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://infrive.ru/uplcv?utm_term=cheat+apk+higgs+domino
    • http://leylasuren.com/images/userfiles/imagefile/84785266462.pdf
    • http://koreabulk.net/userData/board/file/33368636453.pdf
    • https://rougezenekar.hu/files/file/30162396210.pdf
    • http://axwelindia.com/uploads/96345616126.pdf
    • http://yangpupark.com/uploadfile/files/42726702039.pdf
    • http://cautrucpalang.vn/webroot/img/files/xidagododapadeka.pdf
    • http://tencanpowder.com/d/files/kitedazipevufetatulonane.pdf
    • http://swaptoys.org/ckeditor/uploads/files/36146993818.pdf
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/16148957f9887a---50017518679.pdf
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/ar94jksk990e4ommlibis82ot7/gilidi.pdf
    • https://glozor.com/userfiles/file/25718174702.pdf
    • http://rc-modeller.se/images/file///14017983168.pdf
    • http://a2kat.ru/userfiles/file/tosapifinugugo.pdf
    • http://pickup-ws.com/userfiles/files/57394111428.pdf
    • http://xn--80akoseq9f.xn--p1ai/userfiles/file/67335249101.pdf
    • https://fo-prefectures.com/pages/files/jilonijopigonil.pdf
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16135af2743351---sipumevo.pdf
    • https://bda.ch/ckfinder/userfiles/files/42938052119.pdf
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1614bfe8e4e3e9---98012980223.pdf
    • http://phannhan.vn/files/usersfiles/files/xexisamabuva.pdf
    • https://alkathirilaw.com/userfiles/files/nipubawone.pdf
    • http://citranco.com/users/files/wibimagapexapa.pdf
    • http://clear-es.net/yamituki-n/uploads/files/bomegusotijoj.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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d388.bin
2c21ff3ceeb7a5749d3d52712a08aca31fcce6c6a030d08a19a294d8f4050a43
pdf-font-stream PDF embedded font (sfnt) at offset 0xD388 16124 bytes
font_01_sfnt_off0000e8ea.bin
6c08887b596ecb472c5a0482df8c2f828d83fc5b5d16111ed0caa1fced1b35dc
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8EA 1680 bytes
font_02_sfnt_off0000f0e2.bin
4512b5fbc75a3dee6f3b26efe867c480ed69184706ac75a2add43a24c778b182
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0E2 21200 bytes
font_03_sfnt_off000127fd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x127FD 16792 bytes
font_04_sfnt_off00014014.bin
dfa62a20c3e68828b7db9413edb86f940415bbb49850c10591eb2c90b4632503
pdf-font-stream PDF embedded font (sfnt) at offset 0x14014 10816 bytes