Malicious PDF — malware analysis report

Static analysis result for SHA-256 c50537d5efadc176…

MALICIOUS

PDF

91.4 KB Created: 2021-09-08 21:20:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 2795c24004954206e9c4c32830ed59b9 SHA-1: cc096a86fd4c989aac8dce35bdaf9205abeeafed SHA-256: c50537d5efadc176efaaa897c243a32ab750fb4cbdc12ce1c19c344c482e0ebe
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to domains that appear to be part of a link farm, with some hosted on compromised CMS upload directories. The primary function appears to be directing users to external sites, likely for malicious purposes such as phishing or SEO spam.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://chrisdepanneservices.com/Sites/cds/files/pubugodobonad.pdf In PDF document text
    • http://gesundezellen.de/neu/userfiles/file/xijefarol.pdfIn PDF document text
    • http://budaors.varosom.hu/userfiles/files/80000031838.pdfIn PDF document text
    • http://gzafjc.com/uploadfile/files/muzovegazuxoguzaxozisaxo.pdfIn PDF document text
    • https://yp05.com/_UploadFile/Images/file/45551590733.pdfIn PDF document text
    • https://asiantms.com/ckfinder/userfiles/files/lifezemunoko.pdfIn PDF document text
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/81b9f5b107996a70c2ce1a93dad2c61f/98942639299.pdfIn PDF document text
    • http://sanga.asia/userData/board/file/kekijarodesewejajo.pdfIn PDF document text
    • http://coinproject.com/userfiles/image/file/guneluvudurosowilat.pdfIn PDF document text
    • http://bycongroup.com/UserFiles/file/80729477437.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/dtfc43aflqhu29tsf9grer5bgg/94507440541.pdfIn PDF document text
    • https://8cj2aja7-8mxb.com/contents/files/83725215054.pdfIn PDF document text
    • http://precedent.by/_newsite/images_from_html_editor/file/91236236976.pdfIn PDF document text
    • http://ipceurope.com/assets/file/sewulavamipiv.pdfIn PDF document text
    • https://partetesal.ir/data/file/fubobuxolaluwotaze.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/k85k2shpu9h9evt76ehflud9h3/28817960869.pdfIn PDF document text
    • http://tdbm.vn/upload/files/6952340669.pdfIn PDF document text
    • https://tvsporedi.si/vsebina/funexisotitaj.pdfIn PDF document text
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/238fae77e8868f6cbb38e9c6bf5ed491/gokavuwamusewawoti.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134bef0ab4d0---17821052542.pdfIn PDF document text
    • https://study-abroad-travel.com/ckfinder/userfiles/file/ziwivixiw.pdfIn PDF document text
    • http://s-privod.ru/userfiles/file/pitejigazopukafezir.pdfIn PDF document text
    • http://maremio.ru/admin/ckfinder/userfiles/files/misumuve.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=periodos+de+la+filosofia+griega+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_off0000f74c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF74C 10472 bytes
SHA-256: 14f1a76734cf3221c90263bc9c4aaeeed043e03fc29430f09bf7e59b038eb4ea
font_01_sfnt_off00010ef8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EF8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001270a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1270A 21384 bytes
SHA-256: 3754d86c5b678d23bb644bdeb358015a9a1cf92d2ce41cd1612ff8635b0a64b0