Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae12551c9c558a38…

MALICIOUS

PDF

88.2 KB Created: 2021-07-30 00:51:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 2b6c108e05ad80c4763ac5c4486554a5 SHA-1: ef559e7a777c3e84dc5fcaba327c0c2b8d636447 SHA-256: ae12551c9c558a3843bcc165e3eb1bad1e3af0943554f2a9f794a16185fd910c
156 Risk Score

Malware Insights

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

The file is a PDF document detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many pointing to compromised CMS upload directories, suggesting it functions as a link farm to distribute further malicious content or phish users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://www.aukuras.org/ckfinder/userfiles/files/47251077602.pdf In PDF document text
    • https://cruiseship.cruises/wp-content/plugins/super-forms/uploads/php/files/tb1ta2ila5ui1605lqppfek8k2/dajunowedekote.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609863fde2ca2---93537318588.pdfIn PDF document text
    • https://www.gurgy.net/ckfinder/userfiles/files/87659909281.pdfIn PDF document text
    • http://harposwebdesign.nl/app/webroot/files/userfiles/files/nukufaxenobota.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/m0up689efndvbdfv1plda7gf32/82397413184.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c4c2a88aa40---gawapebozezitesigewez.pdfIn PDF document text
    • http://web-news.eu/www/pkpar/userfiles/file/66104550178.pdfIn PDF document text
    • http://risme.vn/files/pomokomadosewipat.pdfIn PDF document text
    • http://americanpetrochemicals.com/customers/CMS-IMAGES/file/gubotixaviwa.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1aafc0af0c---latusiwabovalizof.pdfIn PDF document text
    • https://otartufo.com/ckfinder/tartufofiles/files/jigigapamun.pdfIn PDF document text
    • https://ttnthailand.com/upload/userfile/files/garidalidul.pdfIn PDF document text
    • http://highlevel.pl/userfiles/file/98277861183.pdfIn PDF document text
    • https://www.mds-horizons.com/upload/files/xufaxivinorovo.pdfIn PDF document text
    • http://nfc.soo.jp/file/39634703968.pdfIn PDF document text
    • https://bursac.net/userfiles/file/wimojisubeperolodiwide.pdfIn PDF document text
    • https://drsubhashawale.com/ckfinder/userfiles/files/kixawokapaxototujugemazi.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16091cb8ed8942---74641585621.pdfIn PDF document text
    • http://nwatchonline.net/userfiles/file/nokusuki.pdfIn PDF document text
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d3152387a1---64797389783.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/ecc2cc0a8d5405c685736d883a066c89/metas.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/994c20ef6410088af9dd22bd679297ae/40004577186.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=comprehension+passages+for+grade+4+with+answers+onlinePDF link annotation
    • 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_off0000f45c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF45C 11140 bytes
SHA-256: 93d7c42d13dad0e9dfae1a3fd2544f090867dead4433b7ac8f09c53fed8ec0d6
font_01_sfnt_off00010e1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E1A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001262c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1262C 16824 bytes
SHA-256: 310c1ee5936c6b969a615aabd9b1f219dddb7ad021f30698ff2db1ee7811220d