Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa5aa3def7f33529…

MALICIOUS

PDF

78.9 KB Created: 2021-10-08 00:17:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c0d51ab2076c96882cbb906bcb505528 SHA-1: 9c5f221b4c57685c89fe1a7bc1fba4c51fe532be SHA-256: aa5aa3def7f33529f74530fd0e06ba6f25a875a4ce35c6b0a0564174ce867805
196 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with high-confidence heuristics indicating that some point to compromised CMS uploads and disposable hosting. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the link farm behavior is a clear indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://redondoclassicburger.com/uploads/files/68330511355.pdf
    • http://usateatop.com/_upload/files/fumap.pdf
    • http://newbiesites.com/userfiles/file/sesoletegojipotuwemopo.pdf
    • https://history.tlshaa.org.tw/ckfinder/userfiles/files/mapowekebalusuv.pdf
    • https://accidentmatters.com/ckfinder/userfiles/files/28664774955.pdf
    • http://wmc21.com/ckupload/files/441777322.pdf
    • http://nieruchomosciklodzko.pl/files/file/24051595699.pdf
    • http://nakamurasangyou.jp/app/webroot/uploads/files/xazojexobo.pdf
    • http://clean-ecology.com/Upload/files/4504741936.pdf
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614258eba834b---kowakeketuwisobixopamij.pdf
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/ta4rfa6bddrvqgkt423fuvbj27/29030828519.pdf
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/2193d3d75e782bc6e01e9fc5ba72a58b/24429511816.pdf
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613c96c39ff33---rasotin.pdf
    • https://manorhair.com/uploads/files/202109031329557137.pdf
    • https://onlinendttraining.net/files/nusozipoxitabaletowe.pdf
    • http://goldendoodlesofthesierranevadas.com/userfiles/file/ditorafup.pdf
    • http://luchetti.it/userfiles/files/dawesiguxitokan.pdf
    • https://srmhomes.com/images/bulk_images/files/wajavatubukufad.pdf
    • http://clinicaveterinariagussago.com/userfiles/files/mijepubaxadodibotefuju.pdf
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/50598500361.pdf
    • https://i-try.tw/upfile/files/2021/09/08/wajixebakub.pdf
    • http://hkwwta.org/userfiles/51779018125.pdf
    • http://pzhjintai.com/upload/files/neberiketeku.pdf
    • https://austdoorcaocap.com/upload/files/42615124229.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=good+objective+statement+for+resume
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d0bb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD0BB 16792 bytes
font_01_sfnt_off0000e8cd.bin
b52c5b7561c6f02c7740cfee2326df203ebf37fef853d4fbfa2475ebc5a2613f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8CD 17060 bytes
font_02_sfnt_off00011492.bin
600a90fd0aaccca65e6d2b6ae1cbd6d136a74a098b7a255a811047337617bc81
pdf-font-stream PDF embedded font (sfnt) at offset 0x11492 11064 bytes