Malicious PDF — malware analysis report

Static analysis result for SHA-256 a85fe31cceaee537…

MALICIOUS

PDF

46.9 KB Created: 2020-08-14 23:39:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d90c67e38b5a203f52a524126e404c25 SHA-1: f35cc71d3afc1984099a5980870ded835fde33f1 SHA-256: a85fe31cceaee53771e94cd11aad525feb9fa34649f356a3faa56465e8ba9ba6
152 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for linking to known malicious redirector infrastructure, specifically at https://ttraff.cc/wb?keyword=enfermedad%20de%20addison%20causas%20pdf. The document body also contains this URL and numerous other links to PDF files hosted on various domains, indicating a link farm designed to attract traffic. The ML classifier also strongly flagged this PDF as malicious. The primary attack pattern involves luring users to malicious sites via embedded links.

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/wb?keyword=enfermedad%20de%20addison%20causas%20pdf
    • http://pubegepib.catholicyyc.ca/uploads/1/3/0/7/130775413/3972295.pdf
    • http://files.amityseries.org/uploads/1/3/1/8/131856257/zeriganikud-viwivokuta.pdf
    • http://files.katarinatuffvesonjensen.com/uploads/1/3/2/7/132712369/1511650.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/87678197609.pdf
    • https://cdn.shopify.com/s/files/1/0434/0813/0197/files/gasumigenuwikepa.pdf
    • https://cdn.shopify.com/s/files/1/0432/1568/3744/files/banana_pancakes_ukulele_chords.pdf
    • https://cdn.shopify.com/s/files/1/0427/8134/3900/files/18458806674.pdf
    • https://cdn.shopify.com/s/files/1/0429/1608/5923/files/39857045248.pdf
    • https://cdn.shopify.com/s/files/1/0427/8085/2383/files/dasamokako.pdf
    • https://cdn.shopify.com/s/files/1/0432/2666/1023/files/62456302630.pdf
    • https://cdn.shopify.com/s/files/1/0436/5513/5390/files/inflammatory_foods_list.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006add.bin
9fe44ca2211a86bae76492b4a65f352613a4e683af337c1d099ce3cd0beff75e
pdf-font-stream PDF embedded font (sfnt) at offset 0x6ADD 5028 bytes
font_01_sfnt_off00007bd4.bin
7cd0a04648bf3b2b36501dd14c8a207e85210720934390f110dbd684c9a937e2
pdf-font-stream PDF embedded font (sfnt) at offset 0x7BD4 10872 bytes
font_02_sfnt_off00009f51.bin
ad623bc7c681097dfa1224999cf6cc6072d3ca9a137655dc1129b0261f0b357c
pdf-font-stream PDF embedded font (sfnt) at offset 0x9F51 4324 bytes