Malicious PDF — malware analysis report

Static analysis result for SHA-256 0cf9df8d9cf05827…

MALICIOUS

PDF

76.3 KB Created: 2021-06-08 18:46:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: bec8b377d6b55bd7e22c4bc25de83f58 SHA-1: 5a894660c9fe3f599880aa381c280cbd029d0423 SHA-256: 0cf9df8d9cf05827a98c2b55b1746bd06f6e4b4c6c1e159e378b3c2dcb3c4e50
176 Risk Score

Malware Insights

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

The file is a PDF document that contains numerous embedded URLs pointing to various websites, many of which appear to be compromised WordPress installations. The document body, though heavily obfuscated, suggests an academic context ('Mcq on introduction to macroeconomics'), likely a lure. The presence of multiple external URIs and the ML classifier's high confidence score indicate a malicious intent, likely phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://synerhu.ru/uplcv?utm_term=mcq+on+introduction+to+macroeconomics PDF link annotation
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/bf47462debcbeb3f473b3f73f8dcceb5/katedemokaw.pdfIn PDF document text
    • https://fanaf.comarticle_ressources/file/nerukusokufisiduwoxe.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/1608e87c9bd4a3---zirujezaginefagepogaru.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607acb8755a0c---dasugatuzunuj.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/a9cs48tid8k818fm72vmt74osg/44151852740.pdfIn PDF document text
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/srv17rh1oifkqcbr39717p07sb/90217268403.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a2df417bda0---nepobezegir.pdfIn PDF document text
    • https://aterhesseg.com/up_image/file/wisixebex.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1609103f10d327---87666105325.pdfIn PDF document text
    • http://banglatalkies.com/dynamic-images/cms/file/jadotodav.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d928c9bf23---kenosugeroxikoxepuwipiret.pdfIn PDF document text
    • http://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/160ba9e9a108b7---kininekezezekipawozubeji.pdfPDF link annotation
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/revemolufovevut.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/lpk44tlmi7idhp3b8djlk7iout/kakofid.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d47bdb4139---fopifitudimo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ee23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE23 5184 bytes
SHA-256: 603c3a857d34f2b16b34e7299987e37182ddd96205e2c146bdb774e372a8b29f
font_01_sfnt_off0000ffae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFAE 10856 bytes
SHA-256: 4d26bb433534c565de602f893c0b8f935161ee5bd5aba21ca7418e90c3243cfd