Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1e81688ac9abbe0…

MALICIOUS

PDF

64.6 KB Created: 2020-04-21 02:09:32 +03:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6) First seen: 2026-05-09
MD5: bfdca2dc799b9ef19d1bdca643bdf753 SHA-1: 8b7b2a45b50f19b519ec13d450c4151c661aae5e SHA-256: a1e81688ac9abbe0c9aae1ebc5d480a8ba6e487a0f75a1e3effc4f7d9418e2b8
96 Risk Score

Malware Insights

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

The PDF file contains numerous external links, a technique often used for SEO poisoning or to redirect users to malicious sites. The document body, though heavily obfuscated, contains text related to 'Sherlock holmes all books pdf' and references wkhtmltopdf, suggesting a lure to download or view content from the linked URLs. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9674

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://easyfreelegal.com/uploads/1/3/1/4/131452732/131452732.html#sherlock+holmes+all+books+pdf PDF link annotation
    • http://soida.net/uploads/1/3/0/8/130814805/xogisat_dafarokugofop_zojoxiwowi_kojumeputeve.pdfIn PDF document text
    • http://sidetracks-newzealand.com/uploads/1/3/1/3/131381443/b0660e1aa0.pdfIn PDF document text
    • http://marysnails.org/uploads/1/3/0/5/130550781/3185641.pdfIn PDF document text
    • http://zsecond.net/uploads/1/3/0/4/130476429/vimozos.pdfIn PDF document text
    • http://mountainxllc.com/uploads/1/3/0/6/130605048/4eb8dca7530.pdfIn PDF document text
    • http://honestguy.info/uploads/1/3/1/3/131380583/milog.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://sinhala.sourceforge.net/In PDF document text
    • http://sinhala.cvs.sourceforge.net/viewvc/*checkout*/sinhala/sinhala/fonts/CREDITSIn PDF document text
    • http://www.gnu.org/licenses/gpl-2.0.htmlIn 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_off000069d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x69D7 7832 bytes
SHA-256: 429b7fbf2e2f764beec87f3408d78221433ce0f4e9f64a239e9bb6b93db6df89
font_01_sfnt_off0000880f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x880F 44180 bytes
SHA-256: a106c8aead8cfc42e0b6831661aff33d53d1ea3a1715e29464c2c6a738f0bd2b
font_02_sfnt_off0000e1a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1A7 16028 bytes
SHA-256: ca889182d22413b1a5b6446cd5d954c095bfc2c8b2fec1022b19199100617195