Malicious PDF — malware analysis report

Static analysis result for SHA-256 d3e591573d4db8ca…

MALICIOUS

PDF

78.3 KB Created: 2021-09-18 23:27:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2750909154cdb88efeb01fe648f7ab80 SHA-1: 57b1cf360957ac09d0bb00d24a38c617f42528a5 SHA-256: d3e591573d4db8ca4d79713a5bba35aaf92f2395fe279147e26304a2cb000bf4
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to various external PDF files hosted on potentially compromised or disposable domains. The presence of numerous unknown URLs suggests an attempt to distribute further malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://back2wood.de/userfiles/file/88645482550.pdf
    • http://rooptex.com/uploads/bigusedunorix.pdf
    • http://www.musicboxpiano.com/contentfiles/kidigoxadugusalubaxaj.pdf
    • https://vildmarksjagt.dk/userfiles/file/pifobabe.pdf
    • https://nicklason.se/ckfinder/userfiles/files/37167306119.pdf
    • https://mercerapparelss.com/userfiles/files/xojanat.pdf
    • http://hepiran.com/cache/fck_files/file/gedefaxuj.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/l04e9li74os735s0mmr8638kk1/wanivedumisitodab.pdf
    • http://gpshardorawal.com/hemkunt/userfiles/file/rujuludofesukuruwefad.pdf
    • http://pho32shabu.com/uploads/files/lumigomarogumu.pdf
    • http://bloodfaces.de/attachment/file/4875954979.pdf
    • http://knshzj.com/CKEdit/upload/files/30317806348.pdf
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/16145e4867308f---wururifenijiw.pdf
    • https://inoxquochoang.com/app/webroot/files/images/pages/files/ralalopurukuk.pdf
    • http://okna-kurska.ru/page_edit/_samples/userfiles/files/79533092844.pdf
    • http://decorstore.eu/upload/file/pixajabone.pdf
    • https://topconta.ro/userfiles/file/73173594775.pdf
    • https://aiaciran.org/cache/fck_files/file/rokekeloderoxig.pdf
    • https://protraderin.com/userfiles/file/75762852930.pdf
    • http://uspeh-kursk.ru/ckfinder/userfiles/files/najuzalajenugep.pdf
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/204373ac06696fe3a93af459d0a36e85/lizejuwopezawomuf.pdf
    • http://currycornersugarland.com/admin/images/file/kibitipokuboruvomumi.pdf
    • http://phongkhamthienhoa.org/images/files/bitidatuboxesupe.pdf
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/161446428757ab---90970434565.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=nouns+beginning+with+w
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d1f1.bin
f8c59d95250f59be70ad83fef8b4989e2048baeb61a6cc1ec48167d588a64f70
pdf-font-stream PDF embedded font (sfnt) at offset 0xD1F1 10384 bytes
font_01_sfnt_off0000e977.bin
d422a75e1b94120b7418109a1d7bda83908c5122295f4f12510b3b4aadffa00f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE977 16436 bytes
font_02_sfnt_off000113ba.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x113BA 16792 bytes