Malicious PDF — malware analysis report

Static analysis result for SHA-256 f99a3de82edd88a8…

MALICIOUS

PDF

76.9 KB Created: 2021-09-04 20:43:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: c16bb68f226864d0611e5f4508bf901c SHA-1: 947f5241b0770350688c9c1c921ff7bb979380e1 SHA-256: f99a3de82edd88a8067a92cb6801cf39e93a58c0ff544ca3a075433860e2143c
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to compromised websites and disposable hosting, likely to distribute further malware or phishing content. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics confirms this behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://dongduong.net/Images_upload/files/77875178829.pdf In PDF document text
    • http://studiotecnicobonoli.com/userfiles/files/fagatup.pdfIn PDF document text
    • http://cke.hk/userfiles/20067703106.pdfIn PDF document text
    • https://dichocungtoi.com/userfiles/file/vupogezutexaxaxabevepus.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/fdba0952f39cda9de64f0d5e8141724e/69353066141.pdfIn PDF document text
    • http://www.vljainandco.com/userfiles/files/76029748569.pdfIn PDF document text
    • http://www.pibmg.com.br/ckfinder/userfiles/files/files/vuvekotipeliwagejilezegok.pdfIn PDF document text
    • https://verandapattaya.com/userfiles/files/55020614580.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c52d4e8ba57---1065239641.pdfIn PDF document text
    • http://rosabaum.de/web/editor/files/vutomo.pdfIn PDF document text
    • http://gruppocinofilomarsalese.com/userfiles/files/mafijipasumobivemuvar.pdfIn PDF document text
    • https://bbu.vn/Images_upload/files/mifixilokanonegusugovuk.pdfIn PDF document text
    • http://thetownsendfamily.net/clients/a/ab/ab79602242cca8f930cd52af13df1d51/File/55621728972.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/160afe22d499e5---liles.pdfIn PDF document text
    • https://anmimar.com/royal/userfiles/file/jimekipikelokinowori.pdfIn PDF document text
    • http://elistaprezentow.pl/userfiles/file/miviferemi.pdfIn PDF document text
    • https://beatmuellerfoto.ch/userfiles/files/padoguwaw.pdfIn PDF document text
    • https://upchealth.net/wp-content/plugins/super-forms/uploads/php/files/1a34e3e2f0927d450eb51ceeec330015/24102505356.pdfIn PDF document text
    • http://asianmosaicnyc.com/userfiles/file/wukazedak.pdfIn PDF document text
    • http://quetthe.com/upload/files/dizidubuwuxawew.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/3oi4spkmt2rq0cnu679t4c500j/13571413431.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=rule+float+switch+manualPDF 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_off0000c79a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC79A 10732 bytes
SHA-256: 1593f86d8cc76549c9fceec57b04a4031ab91915eebdbc229b0fd41c0ff3542f
font_01_sfnt_off0000e02a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE02A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f83c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF83C 17764 bytes
SHA-256: 5a51971ec99a1a54d681da9030e993e5bed281b0f1913406e2069d6e42b6ef38