Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5c5de866bc0874e…

MALICIOUS

PDF

82.0 KB Created: 2021-09-07 04:58:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9d25282aea6c61b96db6574ee5341480 SHA-1: fc89edf2c0887d829ee21d9ee73a57adda7200c9 SHA-256: a5c5de866bc0874e28171d3310606b9d6e62c532167d577df70be643a2beb767
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS upload storage and disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links. No scripts were extracted, but the structure and URL analysis point to a common tactic for initial compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ketchas.ru/uplcv?utm_term=fraction+word+problems+with+answers+pdf
    • http://pretaporter-pegah.com/userfiles/file/zulijerixovefotutova.pdf
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092e4ea947e3---93099194429.pdf
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4deead21ac---63333885710.pdf
    • http://allasclub.com/campannas/file/1989146510.pdf
    • https://conexus-study-abroad-travel.com/ckfinder/userfiles/file/fawuloxorim.pdf
    • https://stollerco.com/testingsites/advantage_aviation/assets/media/file/vetugudivo.pdf
    • https://aecvfcom.nrgence.com/upload/userfiles/files/zulopobijinezijawuxezug.pdf
    • http://nuraski.pl/wsg/userfiles/sepezavetovagilol.pdf
    • http://aimecostruzioni.it/userfiles/files/wufemakopiwid.pdf
    • http://shop-cartuning.pl/userfiles/file/70792025081.pdf
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607c58a215267---bewitati.pdf
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/i4rsmqk0ugrpeuk10t1d3tgj36/vavafakerakibumuti.pdf
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160aa401f78c9c---bowokes.pdf
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087297587114---1538003564.pdf
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/7fv0c42isclf89c7m524lhfpn3/tifen.pdf
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/1c62d4929289567e6ff7d2aa2a5c5e75/latabileliwivaxumoz.pdf
    • http://feldbach-tourismus.at/files/loxodizil.pdf
    • http://alfonsoguiggiarchitetto.it/userfiles/files/50438973393.pdf
    • https://www.aledrukujemy.pl/ckfinder/userfiles/files/situdotosapet.pdf
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abc81579e16---24381018382.pdf
    • http://jpsacademy.com/slbdavbatala/userfiles/file/nuginodanawidogudife.pdf
    • http://constantemails.com/userfiles/file/1625430715dazuxovirifakokivu.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_off0000dca2.bin
b1991fc20d7b1e539c90d3b5d2faaed088507cb0f76042e63b94d23a81078ccb
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCA2 17456 bytes
font_01_sfnt_off00010944.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10944 16792 bytes
font_02_sfnt_off0001215b.bin
5b2aa861ebecf842e1824cbe0d99cb36254f7053af073cff6f3613bf94c0e274
pdf-font-stream PDF embedded font (sfnt) at offset 0x1215B 11088 bytes