Malicious PDF — malware analysis report

Static analysis result for SHA-256 a55aecb45cad8336…

MALICIOUS

PDF

45.2 KB Created: 2020-08-03 08:48:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 259a511baa05effaf2e97f8dce74d1f7 SHA-1: 84bc9878f0a30b26a63878ff8a432ca6d291529a SHA-256: a55aecb45cad8336c9818562ec50567f6e93c81622b0db260089937485a5ecad
154 Risk Score

Malware Insights

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

The PDF contains a link to a known malicious redirector, ttraff.ru, which is disguised as a 'necroa virus strategy' document. The document also hosts a large number of links to other PDFs, likely for SEO poisoning or to obscure the malicious redirector. The ML classifier strongly indicated maliciousness, and the embedded URL confirms the malicious intent.

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=necroa+virus+strategy
    • http://files.bluebirdinternetmarketing.com.au/uploads/1/3/1/8/131856146/3700391.pdf
    • http://files.vaughnara.com/uploads/1/3/0/8/130814402/9350035.pdf
    • http://files.hyattville.org/uploads/1/3/0/7/130775380/7575820.pdf
    • http://files.westmauisailandcanvas.com/uploads/1/3/0/7/130739628/ccfb184.pdf
    • https://cdn.shopify.com/s/files/1/0429/2873/4367/files/siri_voices_download.pdf
    • https://cdn.shopify.com/s/files/1/0430/9411/4465/files/85500053212.pdf
    • https://cdn.shopify.com/s/files/1/0430/3349/3658/files/case_for_faith_study_guide.pdf
    • https://cdn.shopify.com/s/files/1/0431/6443/4583/files/wewalaromaxotop.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/280680.pdf
    • https://cdn.shopify.com/s/files/1/0440/4035/6005/files/tuwebadusivulifikuxi.pdf
    • https://cdn.shopify.com/s/files/1/0430/1216/1685/files/lake_barkley_fishing_report.pdf
    • https://cdn.shopify.com/s/files/1/0437/9066/3832/files/85570783884.pdf
    • https://cdn.shopify.com/s/files/1/0433/5288/3352/files/ratowesirikumarejo.pdf
    • https://cdn.shopify.com/s/files/1/0432/8436/5476/files/jejasirawarorutukubiduw.pdf
    • https://cdn.shopify.com/s/files/1/0435/0813/8150/files/89779451544.pdf
    • https://cdn.shopify.com/s/files/1/0437/8597/8013/files/73055054545.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_off00007384.bin
28f6e8371b54d749bf6c245104f46613366b27f3daddcb4558e9cb346453e03f
pdf-font-stream PDF embedded font (sfnt) at offset 0x7384 5064 bytes
font_01_sfnt_off000084e3.bin
37fd955a9e8993ea662393bea3caf318afc31a2b62776c1fb702a6045bde6879
pdf-font-stream PDF embedded font (sfnt) at offset 0x84E3 10272 bytes