Malicious PDF — malware analysis report

Static analysis result for SHA-256 27c8828b6763f4e2…

MALICIOUS

PDF

88.8 KB Created: 2021-09-05 18:13:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 376378219762f65a0465d86f3674a77f SHA-1: e94bc86274919a03dab581e21eceee484b551dcf SHA-256: 27c8828b6763f4e225377518ea64566c6a93a47b29d28853cc1ccfc0fc029a76
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or are part of a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The primary attack pattern involves luring users to external sites via a seemingly innocuous document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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 http://bhttourist.com/upload/fckimagesfile/93439471183.pdf
    • http://www.anclupnapoli.it/userfiles/file/bumerifupusiged.pdf
    • https://tenfci.org/userfiles/file/dupusudabatuvudare.pdf
    • http://strandedtattoo.net/file/demeju.pdf
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1607b4a3f7a543---68154041722.pdf
    • https://fokusmedia.com/images/uploads/20123796388.pdf
    • http://conditum.nl/userfiles/file/rodetagipon.pdf
    • http://lordoptika.hu/files/files/79111863870.pdf
    • http://ttworld.hu/uploads/content_files/files/39476181412.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab3af7b84a2---94427775174.pdf
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d4700651dd3---81905234903.pdf
    • http://apple888.vn/luutru/files/sijibovonalewiwu.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b40f16762f---birapojemulin.pdf
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a25e2577791---30882978412.pdf
    • https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/a42d5aeafe82bb6848ef1765ae669441/tovurevugapeges.pdf
    • https://anukulagrotech.com/userfiles/file/xunasuw.pdf
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c486f9e5b83---kawebimum.pdf
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/160858b7c5530e---20090722089.pdf
    • http://gumberryoleschool.com/clients/33891/File/damawofupogexarotu.pdf
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609dddc16c577---97167492205.pdf
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607fe2f03a891---61106637876.pdf
    • http://leaguengn.com/userfiles/file///moxamuvigajeje.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=velocity+time+graph+worksheet+with+answers+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_off0000f2b6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2B6 16792 bytes
font_01_sfnt_off00010ac8.bin
b84cb9e425d2f65b22e3a82090ce7aa2cab2c7b5f4aac434a5eb938b9c40cb01
pdf-font-stream PDF embedded font (sfnt) at offset 0x10AC8 18556 bytes
font_02_sfnt_off00013b16.bin
ad8b12f21a555991cbea6bf7efcce20a3cea53ccce67967300f83a3bd0c97ca2
pdf-font-stream PDF embedded font (sfnt) at offset 0x13B16 11328 bytes