Malicious PDF — malware analysis report

Static analysis result for SHA-256 619daf42837efdf8…

MALICIOUS

PDF

75.8 KB Created: 2021-09-08 19:31:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 36184f656152dbacd5d733cc9e2be59d SHA-1: 0f1f4e16ecc5a6f776a20b73e9b4f537bd5147d1 SHA-256: 619daf42837efdf8ca7470c4ef032e83a025785032b19fc8ccd1ad3c503ccb57
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as containing a link farm and pointing to compromised CMS uploads, indicating a malicious intent. The ML classifier and ClamAV also strongly indicated maliciousness. The document body is heavily obfuscated, but the presence of numerous URLs suggests the primary purpose is to redirect users to external, potentially malicious, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://laborke.ru/uplcv?utm_term=little+red+riding+hood+original+story+pdf PDF link annotation
    • http://fukaofoods.tw/uploads/files/202109012055011182.pdfIn PDF document text
    • http://hophungvietnam.com/app/webroot/uploads/files/74052530214.pdfIn PDF document text
    • http://nexxstep.nl/userfiles/file/nigevogumegoguxefijawulix.pdfIn PDF document text
    • http://clainvest.pl/userfiles/file/8552274369.pdfIn PDF document text
    • https://predial-rua-nova.pt/056-CovadaLua/images-editor/file/jirurilujabifedid.pdfIn PDF document text
    • http://rayanchem.com/d/files/rirenadajo.pdfIn PDF document text
    • http://e-motyle.natura2000.pl/imgturysta/files/rafexixezuwerizigepaw.pdfIn PDF document text
    • http://bbhshipyard.com/userfiles/file/vedefelodokekig.pdfIn PDF document text
    • http://penzion-u-zamku.cz/files/file/50902544865.pdfIn PDF document text
    • http://yuemeism.com/uploadfiles/files/sezifofitijodojav.pdfIn PDF document text
    • http://thuaphatlailongthanh.vn/upload/contentFile/minhchau/file/7266469410.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613755f637c72---2670051069.pdfIn PDF document text
    • https://davaocarrental.com/images/file/difidalenunefolebumifinum.pdfIn PDF document text
    • http://smlstripedbass.com/home/rock/public_html/ckfinder/userfiles/files/wuzemuvisizafatag.pdfIn PDF document text
    • http://agendatourvietnam.com/hinhanh/file/tepamagorexufedixigik.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/161346823bcf15---74457060512.pdfIn PDF document text
    • http://belloverde.net/emailer/file/35173380715.pdfIn PDF document text
    • https://hargagila.com/uploads/image/files/37780670222.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/161341ed3cdaf4---lipikiki.pdfIn PDF document text
    • http://busto-wl.gattinonimondodivacanze.it/themes/userfiles/files/49661321588.pdfIn PDF document text
    • https://gruppopolidori.com/upload/image/file/91916470530.pdfIn PDF document text
    • 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_off0000c4f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4F7 10848 bytes
SHA-256: a7d5c47b60e758096b6223e1f65c6a1040ff31d377c29e8d10f0b5c44095a7d8
font_01_sfnt_off0000ddbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDBB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f5cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5CD 17232 bytes
SHA-256: 7b5d09751b45c1107dcdf3701c3f1e2dab2f648c4bed3f1daf71b05d0dfe9152