Malicious PDF — malware analysis report

Static analysis result for SHA-256 43a9c1f13fd4fa63…

MALICIOUS

PDF

42.5 KB Created: 2020-08-20 06:54:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 31aec699cdce70b759e96bfdb1c2ddc0 SHA-1: 7b3158e1883dabe6f18f8359b3fdfc582873629b SHA-256: 43a9c1f13fd4fa6398e80009c57904603d6f68e28fa98363149d643cb343d6e3
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link T1059.001 PowerShell

The PDF contains numerous embedded links, with a critical heuristic firing indicating it links to known malicious redirector infrastructure. The document body, though partially corrupted, contains text related to 'ctet question paper 2011' and the malicious URL 'https://ttraff.ru/pify?keyword=ctet+question+paper+2011', suggesting a lure for educational content. The ML classifier strongly flagged this PDF as malicious, supporting the conclusion that it is designed to redirect users to harmful sites.

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.ru/pify?keyword=ctet+question+paper+2011
    • http://zajiwo.capturedbyecp.com/uploads/1/3/1/4/131437508/4570793.pdf
    • http://files.quilteddesires.com/uploads/1/3/1/3/131381612/zagopilot_vokatogidon.pdf
    • https://cdn.shopify.com/s/files/1/0438/7936/6811/files/92087750890.pdf
    • https://cdn.shopify.com/s/files/1/0429/7195/5351/files/vukurorowunezu.pdf
    • https://cdn.shopify.com/s/files/1/0431/5188/4445/files/cengage_physical_chemistry_class_11.pdf
    • https://cdn.shopify.com/s/files/1/0430/0845/8905/files/lirefa.pdf
    • https://cdn.shopify.com/s/files/1/0433/0110/9920/files/14757018593.pdf
    • https://cdn.shopify.com/s/files/1/0434/7035/6632/files/beginner_reading_comprehension.pdf
    • https://cdn.shopify.com/s/files/1/0433/3400/8987/files/whatsapp_plus_apk_ultima_version_2018.pdf
    • https://cdn.shopify.com/s/files/1/0437/5710/9402/files/library_classification_and_cataloguing.pdf
    • https://cdn.shopify.com/s/files/1/0436/2859/3315/files/52368676522.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_off000067ee.bin
0cb7c2f62695dbf60dfa76330f7a152b258bde9edada51a588f853b1ab10d163
pdf-font-stream PDF embedded font (sfnt) at offset 0x67EE 5136 bytes
font_01_sfnt_off0000796c.bin
66d8173d7c8e6b985064e1eeb44eceb810a6597f153a65486907869bffc99335
pdf-font-stream PDF embedded font (sfnt) at offset 0x796C 10576 bytes