Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c4dd4774a05235a…

MALICIOUS

PDF

45.0 KB Created: 2020-03-26 04:31:28 +02:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6)
MD5: dc728d244973e0f437e23d58e9fbe512 SHA-1: 2097b072c067b5d7e5e5e4cdd0ad5d4b7a257b31 SHA-256: 4c4dd4774a05235aa3afdaf42ac4b2255ac396705ae0bfc4a89f0b42e3d0250a
94 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, a technique often used for SEO poisoning or to redirect users to malicious sites. The document body, though partially corrupted, suggests a lure related to 'Trigonometry review worksheet answers'. The ML classifier strongly indicated maliciousness, and the PDF_SEO_LINK_FARM heuristic confirms the presence of a link farm.

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://devonpdxpix.com/uploads/1/3/0/5/130546742/130546742.html#trigonometry+review+worksheet+answers
    • http://fionaheartkitchenshepherd.info/uploads/1/3/0/4/130477126/masedivowudiroduzujo.pdf
    • http://hearttouchaheart.com/uploads/1/3/0/9/130969222/42ff53d12.pdf
    • http://sustainabilitylaboratories.org/uploads/1/3/0/6/130621084/5107674.pdf
    • http://hopmachinebreaks.com/uploads/1/3/0/5/130589104/7173151.pdf
    • http://amielynphotography.com/uploads/1/3/0/6/130621084/lavesugew_jevujadud.pdf
    • http://aelianfinance.com/uploads/1/3/0/5/130589251/2064300.pdf
    • http://drmcontracting.com/uploads/1/3/0/9/130969777/de0872a7ce7.pdf
    • http://thepaulstreetjournal.com/uploads/1/3/0/8/130874352/tupemetav-jowom.pdf
    • http://lambertpropagationnursery.com/uploads/1/3/0/9/130969593/2762550.pdf
    • http://deryn.net/uploads/1/3/0/4/130475923/fifofirejurapo-revilodobofa-diwezege.pdf
    • http://ogrito.net/uploads/1/3/0/7/130776421/jididif.pdf
    • http://yulechengtianshangrenjian.br3h.com/uploads/1/3/0/5/130541465/liporunosozu-wodowabaviw-zisurazer-tipupeji.pdf
    • http://designsbybanner.com/uploads/1/3/0/7/130775001/8cdbf9f02556b.pdf
    • http://www.seedtoatree.com/uploads/1/3/0/2/130288731/pavapari.pdf
    • http://vvs-foreningen.com/uploads/1/3/0/6/130620424/nokuteni.pdf
    • http://autodiscover.offendervictimministries.org/uploads/1/3/0/8/130813848/3656472.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_off00007c10.bin
9c187a54ed49227a88a869ffab0ca1d60950554e33d0a98169c04a3e612b84b6
pdf-font-stream PDF embedded font (sfnt) at offset 0x7C10 8308 bytes
font_01_sfnt_off00009c2b.bin
11eff0542ee112a7a4f3d5fa86892f13f7f7c80edb17354215cea33bb7714487
pdf-font-stream PDF embedded font (sfnt) at offset 0x9C2B 2768 bytes