Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f4e2c5cca778d03…

MALICIOUS

PDF

39.9 KB Created: 2020-08-16 13:18:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: dc8d3e399eef9804466fbc2ffebad9d5 SHA-1: 6302f557fedf4ce34dba1d4f48181249d10b2e17 SHA-256: 9f4e2c5cca778d03605f776a8226bdc21a0f86db912138c0def30dbacd9b2fac
152 Risk Score

Malware Insights

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

The PDF contains a mass external link farm, with one URL pointing to a known malicious redirector infrastructure. The document body, though partially corrupted, contains text suggesting it is a 'social science class 10 cbse guide', which is likely a lure to entice users to click the malicious link. The ML classifier also strongly indicated maliciousness. The primary malicious IOC is the redirector URL.

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.com/pify?keyword=social+science+class+10+cbse+guide
    • http://files.timmahekdds.com/uploads/1/3/1/4/131406303/birep_jabekadoroju_lisafa.pdf
    • https://cdn.shopify.com/s/files/1/0435/4605/0728/files/masopekupupebipuzepakum.pdf
    • https://cdn.shopify.com/s/files/1/0428/3714/7811/files/35257746930.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/xogasetixudaxaw.pdf
    • https://cdn.shopify.com/s/files/1/0435/4854/1079/files/barosma_betulina.pdf
    • https://cdn.shopify.com/s/files/1/0428/9380/3679/files/pokemon_red_and_blue_strategy_guide.pdf
    • https://cdn.shopify.com/s/files/1/0431/3173/2132/files/bachianas_brasileiras_piano.pdf
    • https://cdn.shopify.com/s/files/1/0428/5205/7244/files/69108073989.pdf
    • https://cdn.shopify.com/s/files/1/0435/2330/9727/files/practical_node._js_book_2nd_edition.pdf
    • https://cdn.shopify.com/s/files/1/0437/1188/9573/files/foputukofewolukixufalop.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/xodujanizovu.pdf
    • https://cdn.shopify.com/s/files/1/0436/2698/7680/files/area_of_composite_shapes_worksheet.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_off00005e82.bin
2f11168e48d6ddf832c4aa99e08d09bc46cac9d8e686bb7ec685eb031f921ff4
pdf-font-stream PDF embedded font (sfnt) at offset 0x5E82 5448 bytes
font_01_sfnt_off00007107.bin
1b55410a5c4c59681a5862d40ffd844fa6097a465269c610ec2979b274c38c7b
pdf-font-stream PDF embedded font (sfnt) at offset 0x7107 10040 bytes