Malicious PDF — malware analysis report

Static analysis result for SHA-256 838bc0fb705eccc2…

MALICIOUS

PDF

103.8 KB Created: 2021-08-29 18:04:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: ed735339d6bc112e8cf6c967dbc0cc31 SHA-1: 56da7f923bb299ad5a50bf22f0579c8423ce45ea SHA-256: 838bc0fb705eccc2b2ea3a0473f1a5de053efb0688adfeee161d68d3abde89b6
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to potentially compromised or disposable hosting, suggesting an attempt to distribute malicious content or manipulate search engine results. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://aaaexpressheating.com/userfiles/file/dides.pdf In PDF document text
    • http://bendhorseride.com/userfiles/file/rogova.pdfIn PDF document text
    • http://eros-arena-reutlingen.de/eros/userfiles/file/golorabuwaw.pdfIn PDF document text
    • http://bearcatbb.com/CKEdit/upload/files/kikuwukeganogun.pdfIn PDF document text
    • https://thuaphatlaihoanghuy.com/uploads/files/20999762626.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1be3e1c3a5---68317146954.pdfIn PDF document text
    • http://geodez.com/pliki/file/94714731534.pdfIn PDF document text
    • http://al-bandak.com/userfiles/file/40560540148.pdfIn PDF document text
    • http://ohappy.org/userData/board/file/93574468911.pdfIn PDF document text
    • https://alienaquatics.com/home/gb/public_html/ckfinder/userfiles/files/57846478422.pdfIn PDF document text
    • http://allaboutdowney.com/userimages/sexinixirurowatux.pdfIn PDF document text
    • https://www.zaantraining.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a4624834f33---naguxijofowesotifusiva.pdfIn PDF document text
    • http://sportsclinicwest.ie/media/contents/file/38981241949.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611908cfce4aa---boxemureruvag.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9561079dbb---69645791342.pdfIn PDF document text
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/eb3bda3b71ce3c620f8952a6d9951b5b/94321212513.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/88afc59fae631d838ebae9d149ceaacb/32483041364.pdfIn PDF document text
    • http://kayapaliinsaat.net/file/zajux.pdfIn PDF document text
    • http://www.toeterloeh44.de/files/81067732160.pdfIn PDF document text
    • https://popa.com.br/wp-content/plugins/super-forms/uploads/php/files/8484325157fbae45e77279b268740b01/91387725068.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161177b15d8d25---fiziwanap.pdfIn PDF document text
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a579ad188f6---tipowuwavurexovo.pdfIn PDF document text
    • http://cnc-soustruzeni.cz/files/file/3593872484.pdfIn PDF document text
    • http://greenbrier101.com/userimages/88821211856.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=political+subjectivity+definitionPDF link annotation
    • 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_off00012db1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DB1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000145c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x145C3 19352 bytes
SHA-256: 8307724a70310a295993e9428a8335f2430fac29a4612ba61e51b3a6faf92236
font_02_sfnt_off000177f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x177F7 10920 bytes
SHA-256: 0032e890b5b622932ec8ee17d03c48582cab8ff201f515fac8590957e152ce0c