Malicious PDF — malware analysis report

Static analysis result for SHA-256 4aae039d81bd093c…

MALICIOUS

PDF

107.1 KB Created: 2021-09-12 23:31:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 8073ac116ee21809c090c75f1330885e SHA-1: e2740a6f9c929f563b592c13e1443d6a2a5a89ec SHA-256: 4aae039d81bd093c13e71da39546044ee1e043884bc7e37f7cf68e35a26e6e75
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. The document body was unreadable, but the presence of numerous unknown URLs supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://kop-trans.pl/uploads/userfiles/files/bevasigaxo.pdf In PDF document text
    • http://stroyindustry.com/userfiles/file/bofinaxugokin.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/1502b7ae187284612da67c777e009dc7/75708241209.pdfIn PDF document text
    • http://metapolar.hu/tmp/lowidodevewidev.pdfIn PDF document text
    • http://learnazia.com/fck/imagesfile/redegetavikuvesad.pdfIn PDF document text
    • http://greenld.com/userfiles/96231564193.pdfIn PDF document text
    • https://armagedonspedycja.pl/files/file/waxudivagi.pdfIn PDF document text
    • https://korovin.org/site/img_ufiles/27157032440.pdfIn PDF document text
    • http://mbfeed.vn/upload/files/melotuzovefim.pdfIn PDF document text
    • http://francescasciortino.it/userfiles/files/85312211857.pdfIn PDF document text
    • http://gardatrans.com/content/Files/81838792042.pdfIn PDF document text
    • https://sanghvicranes.com/staging/media/58132102132.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/fb15f2f6ce149eb3db3ad6b68afd0564/11512871949.pdfIn PDF document text
    • https://penzionradvanice.cz/res/file/40842354051.pdfIn PDF document text
    • http://notar-frings.de/userfiles/file/40750494348.pdfIn PDF document text
    • http://charivne.info/images/file/45493866446.pdfIn PDF document text
    • https://cfbadalona.net/ckdata/files/29893183035.pdfIn PDF document text
    • https://dichvuketoansg.com/luutru/files/xolopasamuvodafeso.pdfIn PDF document text
    • http://fmi.lu/userfiles/files/14830101835.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16135df6e002ac---84146293366.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/161301254e8ff9---rinugufefofuno.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/sumumamape.pdfIn PDF document text
    • https://upbilbao.com/ckfinder/userfiles/files/gebujebat.pdfIn PDF document text
    • https://bcm.es/files/galeria/files/5833582679.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=android+auto+playerPDF 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_off00013e71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E71 18680 bytes
SHA-256: d4c348247669ee3f3109a889032ce48e8510cbc032e103174f7dc2a25a327f45
font_01_sfnt_off00016f2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16F2C 10412 bytes
SHA-256: ef14d4c649049eda5dee9dd38d57a24ef9c34ccc7e12d2524d0b0d846685857e
font_02_sfnt_off000186df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x186DF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1