Malicious PDF — malware analysis report

Static analysis result for SHA-256 839877f2c85dc5ba…

MALICIOUS

PDF

56.4 KB Created: 2020-04-19 01:45:28 +03:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6) First seen: 2026-05-08
MD5: 3038061e28337838883b243596b6ef1d SHA-1: e8cec9032e402a6025c9cc0fc10221834173d685 SHA-256: 839877f2c85dc5ba339170b2d7789ed0f83da9419802505a98976a4a54d4f3d8
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document contains a large number of external links, many of which are dynamically generated and point to PDF files. The document body, though heavily obfuscated, contains a URL that appears to be a lure for academic materials. The heuristic PDF_SEO_LINK_FARM indicates a link farm strategy, suggesting the primary purpose is to redirect users to potentially malicious content hosted on numerous domains. No scripts were extracted, but the extensive link farm points to a redirection-based attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 4

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://shiying-cheng.com/uploads/1/3/0/7/130739776/130739776.html#clat+2016+question+paper+and+answer+key PDF link annotation
    • http://buildingwealthadvisorygroup.com/uploads/1/3/0/4/130436180/d2373258230.pdfIn PDF document text
    • http://spurinutrizioneroma.com/uploads/1/3/0/6/130622101/9966742.pdfIn PDF document text
    • http://drjgnd.com/uploads/1/3/1/4/131438093/wubavajiwo.pdfIn PDF document text
    • http://houstonbusinessvoiprates.com/uploads/1/3/1/3/131380992/gopedopexovi-jubuvamig-ramopilutisupem.pdfIn PDF document text
    • http://camalistore.info/uploads/1/3/0/5/130589216/dd14eb12b3ad.pdfIn PDF document text
    • http://instituteforchristianreform.org/uploads/1/3/0/5/130551836/4129775.pdfIn PDF document text
    • http://kbhandmade.com/uploads/1/3/1/3/131397934/vewefap.pdfIn PDF document text
    • http://deckyourdesktop.com/uploads/1/3/0/4/130488251/8374361.pdfIn PDF document text
    • http://ultralateral.ca/uploads/1/3/1/4/131437216/f0c6496.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
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/gpl.htmlIn PDF document text

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000082a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x82A0 8160 bytes
SHA-256: ec157ca50b663f748cc54130c28becba3855b6554a8487840b4dc9b7d7f1eae9
font_01_sfnt_off0000a22d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xA22D 2228 bytes
SHA-256: 236d54f3e2479d5e72da3d1be4616617e509581c3e9108e812f40a19f40d28ff
font_02_sfnt_off0000ac4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAC4C 16224 bytes
SHA-256: da097a8c459adbfdf1b1d97412e41569b305acf822c6e113ff3e46e38a168572
font_03_sfnt_off0000c196.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC196 7040 bytes
SHA-256: e3848c4dc541c32d5ce5378dca88dcc1b5e011d00a776f9305a4c308bb6baeb4

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