Malicious PDF — malware analysis report

Static analysis result for SHA-256 42f813a558406040…

MALICIOUS

PDF

79.8 KB Created: 2021-08-22 23:01:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 53ed32fa5e8a2f191d2f38d5a75ac109 SHA-1: cba1cdb29e868ad2c3826e42ec80f3600839df59 SHA-256: 42f813a558406040683ce6b904176ea4bfceb1b5c2fe93282e7cfc44f9949753
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the presence of multiple external URLs is the primary indicator of compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://chcial.ru/uplcv?utm_term=catcher+in+the+rye+character+quizlet
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c78c5f172f---gususibi.pdf
    • http://muszempilla.com/files/file/kikol.pdf
    • https://alkathirilaw.com/userfiles/files/28305113466.pdf
    • https://adium.ru/userfiles/file/rinikakopokol.pdf
    • https://gamaconsultores.cl/upload/file/maneluwokasemef.pdf
    • http://gz-theoutfit.com/UploadFiles/FCKeditor/20210811213517.pdf
    • https://guruamardaspublicschool.com/userfiles/files/tesejo.pdf
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/qh3epqolrru800kgjn2c9j2381/walovumitotovokip.pdf
    • https://adamant54.ru/userfiles/files/27303633578.pdf
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/loia9vvkroiutdh5nnavfba9hn/xuresasafojapadefebidid.pdf
    • https://mo-space.space/web/img/podborky/files/74198378888.pdf
    • http://innovad-ltd.com/userfiles/file/rubupexag.pdf
    • http://hum-lucknow.org/test/fckeditor/file/1814248804.pdf
    • https://turbooto.vn/upload/files/kerukivifaz.pdf
    • https://censcakmu.org/board/file/files/99818434251.pdf
    • https://qqhanoman.com/contents//files/rozifuvexamavuvawib.pdf
    • http://solarhomepage.ch/fckeditor/editor/images/file/84068480805.pdf
    • https://edcasys.com/ci/userfiles/files/tivabuxuvosavezilabew.pdf
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/8df56122185d2b80f24a861112483c8d/gizunesolujelex.pdf
    • https://alianzatours.com/imagenes/file/pakis.pdf
    • http://moyamoya.center/images/hand_uploaded/files/voporexo.pdf
    • http://www.asslar.de/downloads/futomulowuxanutore.pdf
    • 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_off0000d693.bin
e29903423bd3cd8d7df1e9ea25eb2876e54c597f3a63dce09c0970da9a773990
pdf-font-stream PDF embedded font (sfnt) at offset 0xD693 10492 bytes
font_01_sfnt_off0000ee67.bin
2a855ad88ded19572595b035014fb7f8bf916702fb5274510a43851a12faf65c
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE67 16496 bytes
font_02_sfnt_off00011927.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11927 16792 bytes