Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfbc66644e206e7c…

MALICIOUS

PDF

75.8 KB Created: 2021-03-31 00:49:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 983c97e1fede0064d7e87ebcd38017a0 SHA-1: a783c9821fae8253da88a4c5abc968c3a1886fed SHA-256: cfbc66644e206e7c3c26c10290052bfd9f5432c8b8d2730bf0ae7735f1f22bdc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document contains a large number of external links, many of which are SEO-themed, suggesting an attempt to manipulate search engine results or drive traffic to malicious sites. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and numerous URLs point towards a phishing or link-farming attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://jacksth.ru/wix?keyword=conditional+probability+answer+key
    • https://cdn-cms.f-static.net/uploads/4474465/normal_601b15a54fe43.pdf
    • https://jaxemojemilela.weebly.com/uploads/1/3/4/6/134622921/wujevil_rudixulaluw_nejukere_zusuredav.pdf
    • https://cdn.sqhk.co/tikalijit/FE3icjh/algorithmic_state_machine.pdf
    • http://nonimejusujajo.22web.org/walmart_grocery_ad_tucson.pdf
    • https://cdn-cms.f-static.net/uploads/4387586/normal_6020fd7d7ba1c.pdf
    • https://gavemipaxok.weebly.com/uploads/1/3/2/6/132680822/533943ab692eb.pdf
    • https://cdn.sqhk.co/vemosoveveb/fsijjcs/52170746663.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/tanapilamaxi/despues_de_una_colonoscopia_puedo_comer_normal.pdf
    • https://s3.amazonaws.com/jejulurowev/63266848447.pdf
    • http://rorizupoduvu.epizy.com/acronis_universal_restore_2014_iso.pdf
    • https://s3.amazonaws.com/zagubip/56899399320.pdf
    • https://s3.amazonaws.com/mibiwivanetuj/75364697061.pdf
    • https://s3.amazonaws.com/bipepezuwed/88650223329.pdf
    • https://e22e8d81-f41f-4d51-abb1-39b19d2d32bb.filesusr.com/ugd/96bf9d_5d0a46ed20194a10a5f6dcef89f7d821.pdf?index=true
    • https://ad646471-8556-449a-8150-55a6f6ff724f.filesusr.com/ugd/7a1c5b_99f3ce38bd76424d8ede45d1c49c2481.pdf?index=true
    • https://cc0b58a5-7bf4-4b41-9cd7-d9bc0cd2cc6f.filesusr.com/ugd/6dc98b_ad8a6496fcb641e1811815b9f890d8d8.pdf?index=true
    • 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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e9b7.bin
75a43d19886999f15f33d08981676c91b4fcddc0702f1ac30c3cf8d3373412ab
pdf-font-stream PDF embedded font (sfnt) at offset 0xE9B7 5256 bytes
font_01_sfnt_off0000fbad.bin
36986050ee82250be378d1a728b85476e76193b78b53733cb71e24f8217162cc
pdf-font-stream PDF embedded font (sfnt) at offset 0xFBAD 11120 bytes