Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa35f83767ac704b…

MALICIOUS

PDF

84.5 KB Created: 2021-08-06 16:19:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 091b39ed38c0bcb1a7a3597f863e25b3 SHA-1: 5957717be44309e3459569e2b04427e70224704e SHA-256: aa35f83767ac704bbf649d7567316cfc0dcf97b87c4ccfc135ced5f85ca23e5c
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which are hosted on compromised WordPress installations, suggesting a link farm or phishing lure. The PDF structure and the presence of external links point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://queure.ru/uplcv?utm_term=comparing+plant+and+animal+cells+venn+diagram+worksheet+answers PDF link annotation
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b7ac0df034e---filurufegapewife.pdfIn PDF document text
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/061355915c8a7e0c16eea30930885aeb/lajumozises.pdfIn PDF document text
    • http://aquinasnb68.com/clients/9/9b/9b9a52ed12f3b440fa02b6ce64642487/File/1809495981.pdfIn PDF document text
    • http://alimentosldm.com/userfiles/file/xifaworapawixulal.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/hl9j8dnkascla70qa7534q065u/74029327864.pdfIn PDF document text
    • http://exlluprimebrochure.com/ckupload/files/86971409683.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bedd743d925---zibemeda.pdfIn PDF document text
    • http://lookkorea.net/userfiles/file/momejuramibarep.pdfIn PDF document text
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/qct65l0tln22ahoqo9aomcrkc3/nozetavedujojutaxatedori.pdfIn PDF document text
    • https://walterchiropracticclinic.com/home/walter/public_html/ckfinder/userfiles/files/86002576512.pdfIn PDF document text
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/aef604e7bbf2010a97318acdd6f5524c/didinezigupegaxet.pdfIn PDF document text
    • http://esejsc.com/upload/files/68232551083.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/16072a97bba573---4031463396.pdfIn PDF document text
    • https://kp-bs.ru/upload/files/56079710828.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/2f6cdc0739e6927ea2cb914a87965bf2/5681602670.pdfIn PDF document text
    • https://mokhalasati.com/userfiles/files/ravekopitonanisibadules.pdfIn PDF document text
    • http://gdlianyu.com/uploadfiles/file/zetalutaripiruwularire.pdfIn PDF document text
    • http://aokisuper.com/ckfinder/userfiles/files/26739190170.pdfIn PDF document text
    • http://www.kickcommerce.com/userfiles/file/61620901320.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c736c7df110---31612695562.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/8651829225.pdfIn PDF document text
    • https://cosmeticdermatologymiamibeach.com/uploads/data/files/79481335420.pdfIn PDF document text
    • 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_off0000e2bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2BF 11236 bytes
SHA-256: c39d40fbd650ceb177d3664785c7177fbaa566910296b12883615593da8e64e4
font_01_sfnt_off0000fcba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCBA 17436 bytes
SHA-256: ce0ef5fc20736b451e5632654bd6002f07092012d1784fbe134e826fb395af98
font_02_sfnt_off00012a78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A78 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1