Malicious PDF — malware analysis report

Static analysis result for SHA-256 ee97739518ddfea3…

MALICIOUS

PDF

46.3 KB Created: 2020-03-22 07:19:19 +02:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6)
MD5: cb75616b6d72b2edab4b6f4b5cedc7d4 SHA-1: 974e7f64133f3128f3461948dfb6577759345cac SHA-256: ee97739518ddfea3213e8b4d4bf75c1d5d29443bd8c2d89d6a038769f963a3dc
94 Risk Score

Malware Insights

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

The PDF file contains a large number of external links to other PDF files hosted on various domains, as indicated by the PDF_SEO_LINK_FARM heuristic. The ML classifier also strongly flagged this PDF as malicious. The embedded document body text, though partially corrupted, contains a title related to chemistry and mentions 'wkhtmltopdf', suggesting it might be a lure document. The primary attack pattern appears to be directing users to a network of linked PDF files, potentially for SEO spam or to host further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

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://riversidecountyhistory.org/uploads/1/3/0/7/130775997/130775997.html#compuestos+que+tengan+enlace+covalente+polar
    • http://monicaariasmiranda.com/uploads/1/3/0/6/130640146/5558eb152a32ecd.pdf
    • http://glichtental.net/uploads/1/3/0/2/130270901/veremumezofe_lubojizudezifo_vumaridivex.pdf
    • http://careerwarriornetwork.com/uploads/1/3/0/5/130551971/vutivotaxixiz.pdf
    • http://healingkcs.com/uploads/1/3/0/6/130621310/jarapugumu-bemumil-fupakelage.pdf
    • http://thel14.com/uploads/1/3/0/7/130739026/vozuwadodamuwi.pdf
    • http://ballispoint.com/uploads/1/3/0/6/130620795/b97876c.pdf
    • http://bellakreationsgifts.com/uploads/1/3/0/6/130639563/7982165.pdf
    • http://resource-economics.org/uploads/1/3/0/8/130814254/55029490.pdf
    • http://www.kylielyall.com/uploads/1/3/0/2/130289310/6992160.pdf
    • http://nxlevelgolf.com/uploads/1/3/0/6/130604294/6627242.pdf
    • http://ericadarchelle.services/uploads/1/3/0/8/130873893/muzeravataba.pdf
    • http://www.autotransportesamy.com/uploads/1/3/0/6/130622005/fuboped-kemasukuruzi-mebidupati.pdf
    • http://onewebday.net/uploads/1/3/0/5/130541346/766b67c4b2d0.pdf
    • http://moderntutoringandeducationservices.com/uploads/1/3/0/5/130551140/ruzotowizifi.pdf
    • http://bevingroup.com/uploads/1/3/0/6/130605078/1412cfee232.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_off00007c91.bin
c30c3a05f5e43da36cdc4b348f9f40e9ecb144012d0df03cb726cad1ed8ab4b2
pdf-font-stream PDF embedded font (sfnt) at offset 0x7C91 9352 bytes
font_01_sfnt_off00009ea0.bin
a12b50bc3078adab06879d8d162ace6ac63ff3bcc460f3fb7fd18d41692fb60c
pdf-font-stream PDF embedded font (sfnt) at offset 0x9EA0 3048 bytes