Malicious PDF — malware analysis report

Static analysis result for SHA-256 a53bd3ee2937f9aa…

MALICIOUS

PDF

102.7 KB Created: 2021-07-15 10:31:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a3149540461154183c930e49770b5b10 SHA-1: 3c77eb4f6f7cab2429dac9256d726e012cd41ba6 SHA-256: a53bd3ee2937f9aa97cdd43fb46290839288922bf3f6a67359a38991b90f45bb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or malware distribution intent. It contains numerous external URIs and links to compromised CMS upload storage, suggesting it's designed to lead users to malicious websites. The document body is unreadable, but the heuristics strongly indicate a link farm used for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9874

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://chcial.ru/uplcv?utm_term=wiccan+guided+meditation
    • http://casaperferiesantamariagoretti.com/writable/public/userfiles/file/26186120186.pdf
    • http://harrisonsfamilyreunion.com/clients/62911/File/buvuruvove.pdf
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/2c22e57b56e93c234223d7ad0480e2d6/liwavifuz.pdf
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609deb2bd1563---11795365111.pdf
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/6ee334b61a138fe98dc97a3f6a1f2e20/91187531931.pdf
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607a195d32382---duwuporenetidalim.pdf
    • http://workprohealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607362bc00a4e---dedolalijepevunasetole.pdf
    • https://refour.dk/wp-content/plugins/super-forms/uploads/php/files/089b109d75af541263cfd7b0cc7000f5/woganigijowekoxupuke.pdf
    • https://ipcare.nl/wp-content/plugins/super-forms/uploads/php/files/h1d7b972itk0tgtk58197sv9eg/zajunikexutapu.pdf
    • https://osakadentalcare.com/contents//files/92017396547.pdf
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/160757eaf37493---96920699567.pdf
    • http://stpatricksreunion.com/clients/84553/File/punofavupogekojuvaw.pdf
    • https://minlinart.com/archive/upload/files/6295710755.pdf
    • https://vietnaminsight.biz/ckfinder/userfiles/files/29522373802.pdf
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160abb2c7b74b6---7302099072.pdf
    • http://garmagostaran.com/Upload/file/12599639413.pdf
    • http://perfectthesale.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080f3a708955---94065061773.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1607320d3c3a3e---nasajobuxera.pdf
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bd42727fb6f---47383786593.pdf
    • http://warraichmeats.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bdcc90a6b0---bixobewego.pdf
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/to4rhqvdlvva4rurjju64egdu3/vifako.pdf
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077bb16962cc---xegavidoj.pdf
    • http://grgct.com/ckfinder/userfiles/files/linixadevedevasijo.pdf
    • https://barrierball.cl/ckfinder/userfiles/files/56322602679.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011290.bin
4137572416d68017316131f5f3b07dbbac35bcf8c9d2ed13dc04843deaf25bbb
pdf-font-stream PDF embedded font (sfnt) at offset 0x11290 10492 bytes
font_01_sfnt_off00012a45.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A45 16792 bytes
font_02_sfnt_off00014256.bin
5cd8a120e106fc2d4fc1855603a636a3ce922decfb1b4d98f17a4a5450337c58
pdf-font-stream PDF embedded font (sfnt) at offset 0x14256 16344 bytes
font_03_sfnt_off0001584b.bin
6c1e029849e9587d79d6018beb09e339b62830501f3bfe2acf36b400dfc021e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1584B 20168 bytes