Malicious PDF — malware analysis report

Static analysis result for SHA-256 e5c7882db46a9146…

MALICIOUS

PDF

43.1 KB Created: 2020-08-24 00:36:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: fa34437b8d55266343d050b3e44ec5a3 SHA-1: bd2f612fe449c74f44fa0ee43a12e10c37fd084f SHA-256: e5c7882db46a91464feb4a600fb4699d7f7b3a8523bf0520053bfb9e96a7de33
152 Risk Score

Malware Insights

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

The PDF contains a prominent link that redirects to malicious infrastructure, disguised as a lure for 'free pdf aptitude questions with solutions'. The ML classifier strongly indicated maliciousness, and the presence of numerous external PDF links suggests a link farm or redirection tactic. 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=free+pdf+aptitude+questions+with+solutions
    • http://files.roryjanismiller.com/uploads/1/3/0/7/130775103/e2926bc.pdf
    • http://files.uclasaepi.com/uploads/1/3/1/1/131163914/gevuzadujunusamaki.pdf
    • http://files.chemistrylabmanual.com/uploads/1/3/1/3/131380052/2487410.pdf
    • https://cdn.shopify.com/s/files/1/0433/1274/2550/files/kumirugu.pdf
    • https://cdn.shopify.com/s/files/1/0428/2348/3548/files/neopets_user_lookup.pdf
    • https://cdn.shopify.com/s/files/1/0437/3318/8759/files/43187292622.pdf
    • https://cdn.shopify.com/s/files/1/0432/1827/2417/files/78964684077.pdf
    • https://cdn.shopify.com/s/files/1/0437/1926/2357/files/audio_visual_aids_in_teaching_english.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/banen.pdf
    • https://cdn.shopify.com/s/files/1/0431/2370/3969/files/818089053.pdf
    • https://cdn.shopify.com/s/files/1/0438/6881/5528/files/grade_11_chemistry_book.pdf
    • https://cdn.shopify.com/s/files/1/0435/5942/0063/files/nigerian_snacks_recipe.pdf
    • https://cdn.shopify.com/s/files/1/0432/3000/3358/files/17716211898.pdf
    • https://cdn.shopify.com/s/files/1/0432/6332/8424/files/99741168265.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_off00006029.bin
b10ddee8747e5a0ca665cf44606958f98cc0f1a6694f51725df602eac08b4a17
pdf-font-stream PDF embedded font (sfnt) at offset 0x6029 5304 bytes
font_01_sfnt_off0000723e.bin
84fa7d84f46b45990e41263872a124f4629f9bd7bebd37706747becf4e5eb3a2
pdf-font-stream PDF embedded font (sfnt) at offset 0x723E 14792 bytes