Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1083f0b0dd96fe8…

MALICIOUS

PDF

74.3 KB Created: 2021-09-14 06:01:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: e2d21b1ef40ff729a8e4bfa8de92e926 SHA-1: cfe279f28196cc36a9a50c0d75a890f593028cc2 SHA-256: b1083f0b0dd96fe86427230834f9a677d93fc6565fbf0af0e0e98f6808b824b8
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan payload. It contains an embedded JavaScript stream and numerous external URIs, many of which are hosted on compromised CMS uploads or disposable domains, forming a link farm. The primary purpose appears to be directing users to download further content, likely malicious, under the guise of legitimate files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://synerhu.ru/uplcv?utm_term=super+mario+64+android+download+apk PDF link annotation
    • http://velo.hu/UserFiles/file/9072862548.pdfIn PDF document text
    • http://stcforanebanglore.smcim.com/www/js/ckfinder/userfiles/files/40439949134.pdfIn PDF document text
    • http://maksimetall.ru/files/20770179559.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613798e37b5e2---1095877483.pdfIn PDF document text
    • https://serrechevalier-skifun.com/imagesfile/89872833631.pdfIn PDF document text
    • https://study-abroad-travel.com/ckfinder/userfiles/file/kejiwazusijonazivuf.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/16134b0b013273---79797750754.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/161312ee46afc3---7034072688.pdfIn PDF document text
    • http://ozt.zielonetarasy-cieplice.pl/uploads/userfiles/files/75798938968.pdfIn PDF document text
    • http://csc0898.com/userfiles/file/20210906092914_jis4gm.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/g8uvlf6hu8862023l0tt7u36f1/bokigufetumakumejuzamuwop.pdfIn PDF document text
    • https://ehlibeytalimleri.com/resimler/files/13643726630.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/xubobokikugiwopiw.pdfIn PDF document text
    • http://alpinist.store/sribati/editor/uploadfiles/mukijajuwolij.pdfIn PDF document text
    • https://solidpractise.com/files/userfiles/file/6934437000.pdfIn PDF document text
    • http://abnig.friendship-match.com/upload/files/wezupunatarapuzipu.pdfIn PDF document text
    • https://tebra.si/userfiles/file/2268900611.pdfIn PDF document text
    • https://mitrasuksesku.com/userfiles/file/84686636302.pdfIn PDF document text
    • https://szelvedojavitasmiskolc.hu/files/files/71381990486.pdfIn PDF document text
    • http://www.fonfe.com/uploads/files/7398518229.pdfIn PDF document text
    • https://weekendtripskolkata.com/userfiles/file/warejedirizasusanoxevaw.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec4839ffd3---sagawozexa.pdfIn PDF document text
    • http://constantcontinuity.com/membership/data/files/45462105349.pdfIn PDF document text
    • https://takitech.hu/userfiles/file/vedowivefagoliw.pdfIn PDF document text
    • http://wirheiraten.de/images/file/33673025849.pdfIn 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://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_off0000bdfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDFE 10888 bytes
SHA-256: a5ae5051f31fa732a13e830acb298aff18d9ec5b31c6e3f023173920b3ea539d
font_01_sfnt_off0000d734.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD734 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ef46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF46 16848 bytes
SHA-256: c893a36dbf16a079c675a1be445d8a2dbce261cdf18eb41cd5f3b1f1a6331ebc