Malicious PDF — malware analysis report

Static analysis result for SHA-256 845cd877770cb43f…

MALICIOUS

PDF

83.6 KB Created: 2021-08-15 00:48:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 40f281849ffa97b0b551023e938cce0d SHA-1: 793512fb26ba962aba2ebbae17a23bf1d200880e SHA-256: 845cd877770cb43f2873b1ef850d2257450bb67b57164400f3090ef923703abd
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many of which point to compromised WordPress sites, indicating a link farm designed to distribute malicious content. ClamAV detected this file as a phishing trojan, and ML classifiers also flagged it as malicious. The presence of multiple external URIs and compromised CMS upload links strongly suggests an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/4jbkjaii5a473qqmivv18lhhju/44859349238.pdf In PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16083a514056f0---29764479452.pdfIn PDF document text
    • http://happypalettebnb.com/CKEdit/upload/files/putamuzonotet.pdfIn PDF document text
    • http://china-hold.com/UploadFile/file/20210608132552910.pdfIn PDF document text
    • http://guojingmall.com/userfiles/file///18809015590.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f64ec86490---jomigadi.pdfIn PDF document text
    • http://mobilephleb.com/clients/2/2d/2d2188d13063160162e6e2bbcdac547d/File/16285693103.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/16084b9107395e---jaranevepipot.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/c18a53b0f9f5fb91fcc40f1da563764f/52142347441.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/9urf4c9v0igolmgiiil684hse4/xefatibojovoxet.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5dce9764e8---25905552556.pdfIn PDF document text
    • https://fontaine-eva.fr/userfiles/files/27478565320.pdfIn PDF document text
    • https://www.studioline.ie/ckfinder/userfiles/files/17935529333.pdfIn PDF document text
    • https://sahodayabbsr.com/test/fckeditor/file/saxefesuzerefo.pdfIn PDF document text
    • http://caffepontoni.com/uploads/file/2928685073.pdfIn PDF document text
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/uj2f6unsluv35tln1fjbda61u0/70905226464.pdfIn PDF document text
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/1vblu4lvpt746f5p4mk97proqv/nerinorivemejubodivoboner.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b170311d650---pibuzutadaxosavuvumene.pdfIn PDF document text
    • http://tksvolga.ru/userfiles/file/27963893216.pdfIn PDF document text
    • http://goodwill.pl/userfiles/file/bepobibunisop.pdfIn PDF document text
    • http://francescasciortino.it/userfiles/files/13863308187.pdfIn PDF document text
    • http://mmckno2010.zkosuchdol.info/files/nofesokakirukuboleruf.pdfIn PDF document text
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba7f7287588---88816844782.pdfIn PDF document text
    • https://banktapeunadana.com/tapeunadana/bank2/admin/userfiles/file/dazakiguxug.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=tipos+de+baterias+para+paneles+solares+pdfPDF 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_off0000e09a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE09A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f8ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8AC 18192 bytes
SHA-256: 6210ce5f415a0568b3e9653e9bc27073d6d8ce73e2220276482cb5548ead28c2
font_02_sfnt_off00012666.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12666 10596 bytes
SHA-256: ca1ece595fe85c15e88db663a1f6fbeb5afea69de302d2b36dcd53c3ea1208e9