Malicious PDF — malware analysis report

Static analysis result for SHA-256 83f9858c940645d9…

MALICIOUS

PDF

68.3 KB Created: 2021-09-26 13:45:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4bb7121f5ef05a8475c37d6474147edb SHA-1: 49a135868e9bef724ee2c2622a1d48d9b14cca77 SHA-256: 83f9858c940645d97ee56c7d2f9701ae1efd9ddc1ac7d81def736630bb786104
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised or disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The presence of multiple PDF link farm heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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://dycmc.com/DATA/upload/files/202109141337324476.pdf In PDF document text
    • http://studioassociatoemc.com/userfiles/files/sobolidideb.pdfIn PDF document text
    • https://grancom.by/upload/docs/19212448075.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f27dc8e5fb---vowesaku.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1612f11425cb3c---nituweze.pdfIn PDF document text
    • http://terezszilvia.com/images/uploaded/file/lonexevowipim.pdfIn PDF document text
    • https://www.nvsrolko.org/ckfinder/userfiles/files/71229740541.pdfIn PDF document text
    • https://snqrsl.quebec/upload/editor/file/sesikas.pdfIn PDF document text
    • https://ohcsi.com/ckfinder/userfiles/files/43624367213.pdfIn PDF document text
    • http://mdbim.pl/ubezpiecz/obrazy/file/79253713829.pdfIn PDF document text
    • https://beldapromosyon.com/calisma2/files/uploads/34725002665.pdfIn PDF document text
    • http://www.520amis.com/upload/files/dofuvoludozikofib.pdfIn PDF document text
    • http://cs-golfclub.com/ckupload/files/85454908528.pdfIn PDF document text
    • http://mobilenmr.com/files/files/74939574111.pdfIn PDF document text
    • https://www.abandassociates.com/ckfinder/userfiles/files/xuxegijere.pdfIn PDF document text
    • http://amy-tsai.com/images_express/userfiles/files/73821082545.pdfIn PDF document text
    • http://decaiyun.com/upload/file/210907061943692557i9iauh8vee2h.pdfIn PDF document text
    • https://laznia-radom.pl/userfiles/file/93641221261.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16142feac44694---putame.pdfIn PDF document text
    • http://cabanagarden.hu/editor_up/21217654136.pdfIn PDF document text
    • https://geya99.com/ckfinder/userfiles/files/xujabesofepapopumutev.pdfIn PDF document text
    • http://gevenschoenen.nl/ckfinder/userfiles/files/76242325481.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/015281648bf6cc69e84c6a8130359fd8/temezoxagenela.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=latest+peacock+tv+apkPDF 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_off0000ada4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADA4 15552 bytes
SHA-256: 93943dd024c703a1230e8cd093c2bd771372a341cab01911fcc4f725b4e7aed6
font_01_sfnt_off0000d514.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD514 10140 bytes
SHA-256: 3af509e1d9a9d9bc9e216d1a2673963c50601c6701576dd25edd67a35b822f4b
font_02_sfnt_off0000ebfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBFC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1