Malicious PDF — malware analysis report

Static analysis result for SHA-256 85c6ad9f9bd4c5ac…

MALICIOUS

PDF

82.6 KB Created: 2021-09-09 11:51:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 75b8ebedf8d2e2ab8e40090847964c50 SHA-1: 601c17b829d547b930abca370a6be64508db8fd2 SHA-256: 85c6ad9f9bd4c5ac791b9220441c10a5e1bf9ce287cb902abb101ec48a1a0d78
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous other PDF files hosted on various domains, many of which appear to be disposable or compromised. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users into downloading further malicious content or engaging in phishing. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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://sattosushi.com/uploads/files/bifovewaxaran.pdf In PDF document text
    • https://akvanova.ru/sites/default/files/66681716058.pdfIn PDF document text
    • http://xn--90aoa5aj.xn--p1ai/ckfinder/userfiles/files/baganefi.pdfIn PDF document text
    • http://kvarkeno56.ru/userfiles/file/6069289820.pdfIn PDF document text
    • http://www.sandzthabapanel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1612f316aabef1---2879803235.pdfIn PDF document text
    • http://www.naturhalles.fr/fckeditor/userfiles/file/suvojedinesijidug.pdfIn PDF document text
    • http://ahdjcm.com/upload/files/tuwaxifuzu.pdfIn PDF document text
    • http://hkxhjfc.ltd/uploads/files/20210907002312.pdfIn PDF document text
    • http://raczcsalad.hu/files/bikewagoboferugosixemag.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ede9bee2ae---japasinibafigan.pdfIn PDF document text
    • http://savaksangida.com/resimler/files/51464942024.pdfIn PDF document text
    • http://www.taimaobi.com/admin/ckfinder/userfiles/files/fafofufaguwuxalawesatumu.pdfIn PDF document text
    • http://clickvay.com/upload/files/96228314301.pdfIn PDF document text
    • http://polyacer-ecp.com/userfiles/files/20210901_071814.pdfIn PDF document text
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/bb96912fcf95d9ed673b415f258ebbbd/bapekogepe.pdfIn PDF document text
    • https://al-wesam.com/userfiles/files/viwazivapuz.pdfIn PDF document text
    • https://panelshock.com/userfiles/file/wuradatul.pdfIn PDF document text
    • http://planet-for-events.de/userfiles/file/40328909086.pdfIn PDF document text
    • https://shoppe.everybodyisnotdoingit.org/gift/userfiles/files/11114809771.pdfIn PDF document text
    • https://aqua2go.pl/galeria/file/7215396618.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=terraforming+mars+colonies+rules+pdfPDF link annotation
    • http://louisiana-arts.org.s150269.gridserver.com/siteuploads/editorimg/file/37685545343.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_off0000ded8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDED8 10928 bytes
SHA-256: abb1d21a13b29cc8ea03b5d81e6c6866dba55c8727dc3cc47ccbda64e28e2882
font_01_sfnt_off0000f7dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7DD 17556 bytes
SHA-256: 7ea59e1448bddfba73c0a31d6e45be1348bc405be214191423b882b7eb6ff70c
font_02_sfnt_off00012563.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12563 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1