Malicious PDF — malware analysis report

Static analysis result for SHA-256 c880dcf9f17704d7…

MALICIOUS

PDF

40.4 KB Created: 2020-08-13 14:53:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: df838dcc6f448beb2456b7dc45e24103 SHA-1: 1c6763719e6adb47058476632bd721dd61c66906 SHA-256: c880dcf9f17704d74452ad977e2e33511648875a8f607904669ad61242e68709
154 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many pointing to Shopify domains, which is indicative of a link farm for SEO manipulation. One critical heuristic identified a link to a known malicious redirector at 'https://ttraff.ru/pify?keyword=building+foundation+design+handbook+pdf'. The ML classifier strongly supports the malicious nature of this PDF. The document body, though heavily obfuscated, contains text related to 'building foundation design handbook pdf' and the wkhtmltopdf application, suggesting a lure to disguise malicious links as legitimate document downloads.

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=building+foundation+design+handbook+pdf
    • http://files.mysticmancreations.com/uploads/1/3/0/9/130968926/mazabaramagixer-bobadowoseka.pdf
    • http://files.niloalcala.com/uploads/1/3/0/7/130740073/sumuxo.pdf
    • http://gapuriziz.tchsafjrotc.org/uploads/1/3/1/3/131379578/desuzakev.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/riwemabosemuridaredexe.pdf
    • https://cdn.shopify.com/s/files/1/0431/2114/8061/files/daberumuzufiruzape.pdf
    • https://cdn.shopify.com/s/files/1/0437/2342/3912/files/firus.pdf
    • https://cdn.shopify.com/s/files/1/0433/0101/1614/files/sogopujajibiragedo.pdf
    • https://cdn.shopify.com/s/files/1/0432/2571/0750/files/sitakuda.pdf
    • https://cdn.shopify.com/s/files/1/0430/7078/3645/files/83043595753.pdf
    • https://cdn.shopify.com/s/files/1/0447/0921/6409/files/demonstratives_in_english_exercises.pdf
    • https://cdn.shopify.com/s/files/1/0447/9765/7248/files/microsoft_sway_tutorial.pdf
    • https://cdn.shopify.com/s/files/1/0430/8438/2357/files/cantonese_english_dictionary.pdf
    • https://cdn.shopify.com/s/files/1/0431/1144/8729/files/66441977489.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_off00005fe4.bin
a9d5565b33b481de9496715e4da4b2c4752f4d442c8095aa75718a30f73484a1
pdf-font-stream PDF embedded font (sfnt) at offset 0x5FE4 5460 bytes
font_01_sfnt_off0000726f.bin
e8d8673c51cfbeb270fa3e6a27da385f06637e6cb925aa44edca520183caeddd
pdf-font-stream PDF embedded font (sfnt) at offset 0x726F 10140 bytes