Malicious PDF — malware analysis report

Static analysis result for SHA-256 85f7ea3dc42aaaa3…

MALICIOUS

PDF

74.5 KB Created: 2021-08-21 01:01:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 938113efaa1e2a667968a9ac12f54139 SHA-1: 2e3d4f263f932fd6be5f59d316a17f1ffb3e306b SHA-256: 85f7ea3dc42aaaa3fa301de8e542a9bd1c60b7931afb24faf109276ee6979dee
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised CMS upload storage or disposable hosting. The ML classifier strongly indicated maliciousness, and the structure suggests a link farm designed to distribute traffic or host malicious content. No scripts were extracted, but the overall pattern points to a malicious document likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 5

  • 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://ap116.ru/userfiles/file/xanaruxatagawinuj.pdf
    • https://rybczewice.pl/userfiles/file/liwevikilixoduzujugujim.pdf
    • http://lifecare4all.com/upload/files/fogulirabafotalajumozemep.pdf
    • https://marblobath.com/app/webroot/img/files/wofiwo.pdf
    • http://www.monts.sk/upload_images/file/nutunusadafogusikomivoze.pdf
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/c73a50906cc3827527ed020f24bc3fd6/vedaruvajovumakalon.pdf
    • http://infoegrafica.com/userfiles/files/13573179099.pdf
    • https://angkortaxiservice.com/userfiles/file/88297051810.pdf
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/b7408efa6be99555b555127a90294f5a/93591260240.pdf
    • https://aihr-iadh.org/uploads/FCK_files/file/kutawuleg.pdf
    • http://eurogeographyjournal.eu/admin/fckfiles/file/jigiwevek.pdf
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e20f6613da---70380070895.pdf
    • https://cgeminfos.ma/upload/file/dositosifivolaw.pdf
    • https://valve-toho.com/userfiles/file/69091685969.pdf
    • http://drironcat.com/images/file/gafunonetebawi.pdf
    • https://agrilaui.com/userfiles/file/87400409282.pdf
    • https://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/160787ec6230dd---80284299926.pdf
    • https://kiaavcilar.com/upload/ckfinder/files/63518272412.pdf
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160b3c85aced0b---vajujokonufef.pdf
    • http://jucal.es/images/file/puvufepatumigevuximu.pdf
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/gq31h961kqs1al4o7rkuh5a2s6/24579468587.pdf
    • http://lumieretvie.com/userfiles/file/sewezurafinulubeg.pdf
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160da71d5de495---66019482374.pdf
    • https://abugfreemind.com/userfiles/file/jizapede.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=karek%C3%B6k+ayt+matematik+mps+%C3%A7%C3%B6z%C3%BCmleri
    • 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_off0000bdb5.bin
dcd7fe9c4f3535175e4320f038a3030b41f452c17f7dfd989d555eb4e94f43a0
pdf-font-stream PDF embedded font (sfnt) at offset 0xBDB5 11052 bytes
font_01_sfnt_off0000d73a.bin
76421979809d819dbfa311e39d215d3ac0a6a6f99e081329cebe541825b67564
pdf-font-stream PDF embedded font (sfnt) at offset 0xD73A 17252 bytes
font_02_sfnt_off00010179.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10179 16792 bytes