Malicious PDF — malware analysis report

Static analysis result for SHA-256 baab4c87f8c9cb89…

MALICIOUS

PDF

40.6 KB Created: 2020-08-17 08:58:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: eb5ee2b506c32be8876bce3f78b62261 SHA-1: b1bc8e26e90b649b0c311e33bbb2f08ebbc6388b SHA-256: baab4c87f8c9cb898cec9ee5f9f8d357669da8656490031fc77e1d13f815b451
154 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic firing indicating a malicious redirector. The document body, though partially corrupted, suggests a lure related to 'Addition of integers free worksheets'. The primary malicious IOC is the redirector URL, which likely leads to further malicious content. The ML classifier strongly supports the malicious nature of this PDF.

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.cc/pify?keyword=addition+of+integers+free+worksheets
    • http://jukulem.listerrentsequipment.com/uploads/1/3/1/6/131636954/fizejezodij.pdf
    • http://files.perkiblog.com/uploads/1/3/1/6/131606256/torud_nofuzat_zefuk_wenirinirarobo.pdf
    • http://files.volgagermansportland.info/uploads/1/3/0/7/130738484/b7d9becfc16.pdf
    • https://cdn.shopify.com/s/files/1/0434/0131/4456/files/30802508405.pdf
    • https://cdn.shopify.com/s/files/1/0436/3275/4841/files/quantitative_data_analysis_in_research_methodology.pdf
    • https://cdn.shopify.com/s/files/1/0430/3699/9842/files/34475448789.pdf
    • https://cdn.shopify.com/s/files/1/0428/2921/7958/files/uc_browser_8._3_java_version.pdf
    • https://cdn.shopify.com/s/files/1/0429/7061/1861/files/automating_the_boring_stuff_with_python_download.pdf
    • https://cdn.shopify.com/s/files/1/0436/0005/2387/files/83749621092.pdf
    • https://cdn.shopify.com/s/files/1/0429/1143/2857/files/33668667212.pdf
    • https://cdn.shopify.com/s/files/1/0430/7252/0352/files/centos_7_admin_guide.pdf
    • https://cdn.shopify.com/s/files/1/0431/9690/7678/files/43032400030.pdf
    • https://cdn.shopify.com/s/files/1/0429/1896/9507/files/2020_cadillac_ct6_brochure.pdf
    • https://cdn.shopify.com/s/files/1/0433/1975/4907/files/25162155640.pdf
    • https://cdn.shopify.com/s/files/1/0435/8701/0715/files/92354687250.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_off000060e5.bin
c8340067abbf363f1e92e05f1aedf08a5df553324271222a7fad598e80fc02d8
pdf-font-stream PDF embedded font (sfnt) at offset 0x60E5 5072 bytes
font_01_sfnt_off00007239.bin
4f583f9def361f9a35020614e9deb5dfb2dc673f9bb770f4e0d317d1c31687ba
pdf-font-stream PDF embedded font (sfnt) at offset 0x7239 10372 bytes