Malicious PDF — malware analysis report

Static analysis result for SHA-256 21d5d68e1e188d6c…

MALICIOUS

PDF

35.8 KB Created: 2020-08-24 05:30:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 19cd5ae26b457690bd46b07f040984ae SHA-1: f6cddd32c89a7900b5962ca0deb9d1fd78c10da7 SHA-256: 21d5d68e1e188d6c5329c85d66879669bdac6f32c4ec1cd2febb004e57118bb5
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains numerous embedded links, with one specifically pointing to a known malicious redirector. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, contains a URL that matches the malicious redirector, suggesting the document's primary purpose is to drive traffic to malicious sites. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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 https://ttraff.com/pify?keyword=libros+de+a.+b.+simpson+pdf
    • http://muboru.rottencollective.com/uploads/1/3/2/3/132302942/8230068.pdf
    • http://jofinak.coolanniestravels.com/uploads/1/3/0/7/130775531/nexobisor.pdf
    • http://files.claytonbrowneortho.com/uploads/1/3/2/3/132302960/1f0ad16.pdf
    • http://gepatix.phillibertplantnursery.com/uploads/1/3/0/8/130873995/467303.pdf
    • http://mapiri.thepaperbackblog.com/uploads/1/3/1/4/131482995/puximone.pdf
    • https://cdn.shopify.com/s/files/1/0430/8425/1285/files/buvomabosuminuwerajazeruv.pdf
    • https://cdn.shopify.com/s/files/1/0439/6164/7262/files/lokij.pdf
    • https://cdn.shopify.com/s/files/1/0438/4414/1218/files/accidente_cerebrovascular_transitorio.pdf
    • https://cdn.shopify.com/s/files/1/0427/7737/8972/files/gubovagopo.pdf
    • https://cdn.shopify.com/s/files/1/0432/6581/8789/files/ripelikegenitod.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/11783771814.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/27588499931.pdf
    • https://cdn.shopify.com/s/files/1/0438/1035/7405/files/wagiwiwivajitujakomewup.pdf
    • https://cdn.shopify.com/s/files/1/0448/3871/5552/files/95_country_code.pdf
    • https://cdn.shopify.com/s/files/1/0439/4539/4331/files/android_messages_for_web_not_showing_up.pdf
    • https://cdn.shopify.com/s/files/1/0436/4389/5958/files/67350459708.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_off00004dfa.bin
f1d1c23e3f3f67d23e39aae3dc95689cdcdd5f6bd28ae3c0dae6a12f4df5b26a
pdf-font-stream PDF embedded font (sfnt) at offset 0x4DFA 5268 bytes
font_01_sfnt_off00005fc8.bin
63b1f783359746c6b8d67ed7bf8575ff294badd1d8b2f46f9501a67a263e3305
pdf-font-stream PDF embedded font (sfnt) at offset 0x5FC8 10256 bytes