Malicious PDF — malware analysis report

Static analysis result for SHA-256 34ae7efa94a93cd1…

MALICIOUS

PDF

53.1 KB Created: 2020-03-26 04:42:00 +02:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6) First seen: 2020-09-24
MD5: 0327bfc76e7aa42cd11fbd090890067e SHA-1: d785b0476090333a71370a7449ffbbf210b782e9 SHA-256: 34ae7efa94a93cd1cf17a90f0d7adb7dd2475a7f506b713d189eb3ad83437d13
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier. It contains a large number of external links, a technique often used for SEO manipulation or to distribute further malicious content. The document body, though partially corrupted, contains the phrase 'Acuerdo de evaluacion aprendizajes clave' and references 'wkhtmltopdf', suggesting a lure related to evaluation or learning materials, which is then used to mask the link farm. No scripts were extracted, but the primary malicious function appears to be the distribution of links.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • ClamAV: Pdf.Dropper.Agent-8919234-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-8919234-0
  • 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://avatarbiotechnologies.com/uploads/1/3/0/9/130969674/130969674.html#acuerdo+de+evaluacion+aprendizajes+clave PDF link annotation
    • http://hostmaster.nottageprimary.com/uploads/1/3/0/5/130588894/jazus.pdfIn PDF document text
    • http://bballguru.com/uploads/1/3/0/5/130539926/kedefogaximogoj.pdfIn PDF document text
    • http://www.contabilizeja.com/uploads/1/3/0/7/130775557/4571983.pdfIn PDF document text
    • http://visionbystin.com/uploads/1/3/0/7/130740375/nalunazuwojixogivit.pdfIn PDF document text
    • http://artistjacquespepin.com/uploads/1/3/0/8/130813369/4191305.pdfIn PDF document text
    • http://momsandi.com/uploads/1/3/0/6/130621024/600053.pdfIn PDF document text
    • http://katafund.net/uploads/1/3/0/7/130776826/0bf750b3706b6.pdfIn PDF document text
    • http://fitosrestaurant.com/uploads/1/3/0/2/130270768/5026412.pdfIn PDF document text
    • http://biomeculture.com/uploads/1/3/0/3/130323175/3a02e.pdfIn PDF document text
    • http://haarlemmermeerkiest.nl/uploads/1/3/0/3/130379352/rubuzupagasinegepap.pdfIn PDF document text
    • http://hinomotorsnuevaecija.com/uploads/1/3/0/4/130479312/fugikawawivobasajir.pdfIn PDF document text
    • http://mail.raritanvalleybassmasters.com/uploads/1/3/1/1/131164130/taxajonipugixun-lunoxego-gosan.pdfIn PDF document text
    • http://daycare-playgroundequipment.com/uploads/1/3/0/3/130313410/cf1b990a2775.pdfIn PDF document text
    • http://fontawesome.iohttp://fontawesome.io/license/In 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00009b1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9B1A 1588 bytes
SHA-256: 7d0e4f26927737c593ed7efda103a1107150fe3ac8ddbcafaf6ee6c0af50a0b0
font_01_sfnt_off0000a2cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xA2CF 9636 bytes
SHA-256: 0188e6789af8737a4bdaac3eb0c9bf8e4d36e1776402c9d11cfdb19269d72b6e