Malicious PDF — malware analysis report

Static analysis result for SHA-256 82a558124465447b…

MALICIOUS

PDF

47.4 KB Created: 2020-05-22 14:16:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1a7d75aa026e992b5a59b3a4f36ba2a3 SHA-1: aa5bf36ff695c5aaa6a62842f8292599686ea25d SHA-256: 82a558124465447b40e10d7bfc2f2f95d8fc8bf23e90e6d82bb734882d867afd
94 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded external links, flagged by the PDF_SEO_LINK_FARM heuristic. The ML classifier also strongly indicated maliciousness. The document body, though partially corrupted, contains text related to 'Mechanics of materials 2nd edition' and the wkhtmltopdf application, suggesting a lure document. The primary attack pattern involves directing users to a multitude of external URLs, likely for SEO spam or to host further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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://host171.carmichaelnl.com/uploads/1/3/0/6/130604420/130604420.html#mechanics+of+materials+2nd+edition
    • http://doggiedeluxe.com/uploads/1/3/1/6/131607635/danoled_vawinafuj_luzeleja.pdf
    • http://lillichart.com/uploads/1/3/1/6/131606597/4379912.pdf
    • http://mybiginterview.com/uploads/1/3/1/4/131408086/wumipawaku_lurifex.pdf
    • http://veganagogoorganics.com/uploads/1/3/1/4/131483371/wuzosabixanuxabu.pdf
    • http://zachbebel.com/uploads/1/3/0/5/130551597/6959102.pdf
    • http://harrisonyearbooks.com/uploads/1/3/1/3/131380305/lixilupusun-fafelexejis-zusadatibak-latul.pdf
    • http://mail.bigcreekkennels.com/uploads/1/3/0/5/130588248/patoluzokodewukexu.pdf
    • http://joconnorbandproject.com/uploads/1/3/0/7/130775049/8373583.pdf
    • http://alluneedonline.net/uploads/1/3/0/5/130550827/45c6fc78a1e946.pdf
    • http://crochetbling.com/uploads/1/3/0/4/130477468/2898548.pdf
    • http://thebritishhotel.net/uploads/1/3/0/2/130271158/890cd.pdf
    • http://hearyeinvitations.com/uploads/1/3/0/8/130815277/zixezifupepofagak.pdf
    • http://joelleallencounselling.com/uploads/1/3/0/7/130739404/dajomanegitakas-mafakul-vexedewa-zowidipevox.pdf
    • http://michaelmccormackarts.com/uploads/1/3/0/4/130488884/2943525.pdf
    • http://sienahoefling.com/uploads/1/3/0/5/130588833/pupedujudofumo-mafejirufedow-gekijarot.pdf
    • http://watatkd.com/uploads/1/3/0/5/130588685/farutosidi-voxugexubugavu.pdf
    • http://redefinetherapy.org/uploads/1/3/0/5/130539114/6122300.pdf
    • http://jdsalazarproductions.com/uploads/1/3/1/6/131637830/21201d921.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000744a.bin
85773914939d32ec3cea1263a34be520b990a98511063ca0ac6d6e45b2fdf7ef
pdf-font-stream PDF embedded font (sfnt) at offset 0x744A 10424 bytes
font_01_sfnt_off000097b9.bin
7a1c3a1409cadba5655e718208952661d75bb35cb30a5ac3e370bea4f6b7683e
pdf-font-stream PDF embedded font (sfnt) at offset 0x97B9 17436 bytes